1

SIMPLE INTEREST .

100

P N RS I

Where, S.I = Simple Interest, P = Principal, R = Rate percent per annum, N= Number of years Amount (A) = Principal + Interest

Recurring Deposit

COMPOUND INTEREST

When interest is compounded annually:

Amount 1 . 1

100 100

N NR R

P C I P P

TNPSC GROUP – I MAIN 2017 GENERAL MENTAL ABILITY

SIMPLE & COMPOUND INTEREST PROFIT & LOSS

2

WORKSHEET

1. Mohan borrowed Rs.20000 from a Bank and returned an amount of Rs.21200 with interest after 219 days. Find out the rate of interest, Nkhfd; xU tq;fpapypUe;J &.20>000I fldhfg; ngw;W> 219 ehl;fs; fopj;J &.21>200 Mf tl;bAld; nrYj;Jfpwhh;. tl;b tPjj;ijf; fz;Lgpbf;fTk;.

2. Deepan invests a certain sum at 20% per annum simple interest. In

how many years it will become six times? jPgd; xU Fwpg;gpl;l njhifia Mz;Lf;F 20 tpOf;fhL vd;w rhjhuz tl;b tPjj;jpy; KjyPL nra;fpwhh;. me;jj; njhif vj;jid Mz;Lfspy; MW klq;fhf MFk;?

3

3. If a sum of money at simple interest becomes 4 times of itself in 15

years, it will become treble in xU njhifia jdp tl;bapy; KjyPL nra;jhy; 15 Mz;Lfspy; ehd;F klq;fhfpwJ. mJ vj;jid Mz;Lfspy;> mNj tl;b tPjj;jpy; %d;W klq;fhFk;?

4. A certain sum of money amounts to Rs 8,880 in 6 years and Rs 7,920

in 4 years. Then the rate percent is xU Fwpg;gpl;l mryhdJ 6 tUlq;fspy; &. 8>880 MfTk; 4 tUlq;fspy; &. 7>920 MfTk; khWfpwJ vdpy; tl;btPjk;

4

5. A person invests a certain sum at a certain rate of simple interest for

5 years. Had he invested it at 3% higher, he would have earned Rs.510 more. Calculate the sum he invested. xU egh; xU Fwpg;gpl;l njhifia xU Fwpg;gpl;l tl;b tPjj;jpy; 5 Mz;LfSf;F KjyPL nra;fpwhh;. mth; mij 3 rjtPjk; mjpfkhf KjyPL nra;jpUe;jhy;> mtUf;F NkYk; &.510 fpilj;jpUf;Fk;. mth; KjyPL nra;j njhifiaf; fz;Lgpbf;fTk;.

6. A sum of Rs.800 is lent into two parts such that if one part be put out

at 5% and the other at 9%, the whole annual interest from both the investment is Rs.48. The first part of the sum is...

5

&.800 vd;w njhif ,uz;L gFjpfshf tl;bf;F tplg;gLfpwJ. xU gFjpf;F 5 tpOf;fhL tl;bAk; ,uz;lhtJ gFjpf;F 9 tpOf;fhL tl;bAk; t#ypf;fg;gLfpwJ. ,e;j ,uz;L KjypLfspy; ,Ue;Jk; xU Mz;L KOtJf;Fkhd tl;bahf &.48 t#ypf;fg;gLfpwJ. vdpy;> Kjy; gFjp njhif vt;tsT?

9. Imran deposits Rs.400 per month in a post office as R.D for 2 years.

If the rate of interest is 12% find the amount he will receive at the end of 2 years. ,k;uhd; Xh; mQ;ryfj;jpy; 12% tl;bapy; xt;nthU khjKk; &.400-I 2 Mz;LfSf;F nrYj;jp te;jhh;. ,uz;L Mz;Lfs; Kbtpy; mtUf;F fpilf;Fk; njhif vt;tsT?

6

10. The cost of a dining table is Rs. 8,400. A wants to buy it in 10

installments. His E.M.I is Rs. 875. Find the rate of interest? Xh; czT Nkirapd; mlf;ftpiy &.8>400.A ,k;Nkiria 10 khjj;jtizfspy; ngw epidf;fpwhh;. mtuJ khjj; jtiz &.875 vdpy; tl;b tPjk; vd;d?

7

11. What annual installment will discharge a debt of Rs.2450 due in 4

years at 15% simple interest? &.2450 flid 4 Mz;Lfspy; 15 rjtPjk; jdp tl;b mbg;gilapy;> Mz;L jtizj; njhifahf vt;tsT &gha; nrYj;jp milf;fyhk;.

12. The compound interest on Rs.10,000 for 3 years at 10% per annum is

(Rs.) mry; njhif &.10>000f;F 3 tUlq;fspy; &.10 tl;b tpfpjj;jpy;

fpilf;Fk; $l;L tl;b

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13. Find compound interest of ì 10000 for 3 years if rate of interest is 5%,

10% and 20% for first, second and third years respectively. %d;W Mz;LfSf;fhd tl;b tPjk; Kjy;> ,uz;L kw;Wk; %d;whk; Mz;Lf;F KiwNa 5 tpOf;fhL> 10 tpOf;fhL kw;Wk; 20 tpOf;fhL vdpy;> &gha; 10>000f;F 3 Mz;LfSf;F $l;L tl;biaf; fz;Lgpbf;fTk;.

14. The compound interest on Rs.5,000 at 16% per annum for 1 year

compound half-yearly is 16% $l;L tl;bapy; &.5>000f;fhd xU tUl tl;b ($l;L tl;b 6

khjj;Jf;F xUKiw Nrh;f;fg;gLifapy;)

9

15. Find out the compound interest on Rs.1,25,000 for 9 months at 8%

per annum compounded quarterly. &.1>25>000f;F Mz;Lf;F 8 rjtPjk; vd;w tl;b tPjj;jpy; 9 khj fhyj;jpw;F> fhyhz;Lf;F xU Kiw fzf;fpLtjd; mbg;gilapy; vt;tsT $l;L tl;b fpilf;Fk;?

16. A merchant commences with a certain capital and gains annually at

the rate of 20% compound interest. At the end of 3 years, he is worth Rs.21,600. What was the original capital?

xU tzpfh; xU Fwpg;gpl;l KjyPl;ilf; nfhz;L xU njhopiyj; njhlq;fp> Mz;Lf;F 20 rjtPjk; vd;w mstpy; $l;L tl;b

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ngWfpwhh;. 3 Mz;Lfspd; Kbtpy;> mtUila kjpg;G &.21>600 vdpy;> mtUila KjyPL vt;tsT vd;W fz;Lgpbf;fTk;?

17. The time in which Rs.6250 will amount to Rs.6760 at 4 p.c.

compound interest &.6,250 I 4 rjtPj $l;Ltl;bapy; vj;jid Mz;Lfspy; mjd;

nkhj;jj;njhif &.6760 Mf khWfpwJ?

18. At what rate percent per annum will Rs.15,625 amount to Rs.19,683

in 3 years at Compound interest? &.15,625 njhifahdJ 3 Mz;Lfspy; Mz;Lf;F vj;jid rjtPjk;

vd;w $l;L tl;bapy; &. 19,683 Mf khWk;?

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19. At what rate percent compound interest does a sum of money

become nine fold in 2 years? $l;L tl;b Kiwapy;> xU njhifahdJ ,uz;L Mz;Lfspy; xd;gJ klq;F Mfpd;wJ vdpy;> mjd; tl;b tPjk; ahJ?

20. A sum of money placed at compound interest doubles itself in 6

years. It will amount to 32 times itself at the same rate of interest in.. $l;L tl;b mbg;gilapy; itf;fg;gl;l njhif MW Mz;Lfspy; ,uz;L klq;fhfpwJ. mNj tl;b tPjj;jpy; me;jj; njhif 32 klq;F Mtjw;F vj;jid Mz;Lfs; MFk;?

12

21. A sum of money becomes Rs.45,000 after 2 years and Rs.64,800

after 4 years on compound interest. The sum is... xU Fwpg;gpl;l njhif $l;L tl;b mbg;gilapy;> ,uz;L Mz;Lfspy; &.45>000 MfTk;> 4 Mz;Lfspy; &.64>800 MfTk; MfpwJ vdpy;> me;jj; njhifiaf; fz;Lgpbf;fTk;.

22. If the simple interest on a sum of money for 2 years at 2% per

annum is Rs.40. What is the compound interest on the same sum at the same rate and for the same time?

xU Fwpg;gpl;l njhiff;F Mz;Lf;F 2 rjtPjk; vd;w mbg;gilapy;> 2 Mz;Lfspy; &.40 jdp tl;b fpilf;fpwJ vd;why;> mNj

13

njhiff;F> mNj tl;b tPjj;jpy;> mNj fhy msTf;F $l;L tl;b vt;tsT fpilf;Fk;.

23. If the compound interest on a sum for 2 years at 10% per annum is Rs.105, the simple interest on the same sum at the same rate for the same period of time is ...

xU Fwpg;gpl;l njhiff;F 2 Mz;L fhyj;jpy;> Mz;Lf;F 10 rjtPjk; vd;w tl;b tPjj;jpy; &.105 $l;L tl;b fpilf;fpwJ vd;why;> mNj njhiff;F mNj tl;b tPjj;jpy; mNj fhy msTf;Ff; fpilf;Fk; jdp tl;b vt;tsT?

24. The difference between the compound interest and the simple

Interest on a certain sum of money at 5% per annum for 2 years is Rs 1.50. Find the sum. ,uz;L Mz;LfSf;F 5% tl;b tpfpjj;jpy; jdptl;b> $l;L tl;b

,itfspd; tpj;jpahrk; &. 1.50 vdpy;> mry; vt;tsT?

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25. A man divided ` 6200 in two parts and lent the first part @ 6% for 5 years, and the second part @ 10% for 4 years. If interest earned on two parts is in the ratio of 4: 5, find the first part.

xUth; &.6200 I ,uz;L gFjpfshf fld; nfhLj;jhh;. Kjy; gFjp flDf;fhf 5 Mz;LfSf;F 6rjtPj tl;bAk; kw;Wk; ,uz;lhtJ> flDf;fhf 4 Mz;LfSf;F 10rjtPj tl;bAk; ngWfpwhh;. mtUf;F fpilj;j ,uz;L tl;bj;njhiffspd; tpfpjk; KiwNa 4:5 vdpy; Kjy; gFjp fld; njhif vt;tsT.

TNPSC GRP – I MAIN PREVIOUS YEAR QUESTIONS

1. The interest on a certain principal amount at 10% per annum compounded half yearly for 6 months is Rs. 2,100. Find the amount invested.

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Mz;bw;F 10% tPjk; miuahz;by; $l;L tl;b fzf;fPly; %yk; Fwpg;gpl;lj; njhiff;F 6 khjq;fSf;Fg; ngwg;gl;l tl;bj; njhif &. 2>100 vdpy;> KjyPL nra;ag;gl;lj; njhifiaf; fhz;f.(3 Mark)

2. A sum of Rs, 2,000 is deposited in a bank which pays compound

interest for the first year at r % per annum and for the second year at 5% per annum. If the maturity amount at the end of second year is Rs. 2,163, find the value of r. (15 Mark Section q.no. a) tq;fp xd;wpy; &. 2000 Nrkpg;G njhifahf nrYj;jg;gLfpwJ. $l;L tl;b mspf;Fk; tq;fpahdJ Kjy; Mz;bw;F r% tl;bAk;> ,uz;lhk;

Mz;bw;F 5% tl;bAk; mspf;fpwJ. ,uz;lhk; Mz;L Kbtpy;

ngwg;gl;l Kjph;Tj; njhif &. 2.163 vdpy; r-,d; kjpg;gpid fhz;f.

3. At what rate percent per annum at simple interest will a sum of

money double in 8 years? vl;L tUlq;fspy; xU njhif ,ul;bg;ghf Ntz;Lnkdpy; Mz;Lf;F fzf;fplg;gLk; jdp tl;b tpfpjk; vd;dthf ,Uf;f Ntz;Lk;? (3 Mark)

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4. The difference between the compound interest and simple interest

on certain sum at 8% per annum for 2 years is Rs. 240. Find sum. tUl tl;b 8% w;F 2 Mz;Lfspy; xU njhiff;fhd $l;Ltl;b

kw;Wk; jdptl;bf;fhd tpj;jpahrk; &. 240 vd;why; mry; njhifiaf; fhz;f.

(DEO MAIN - 8 Mark)

5. Divide Rs. 5,450 into 3 parts so that the respective amounts at 4, 5, 6 per cent in 3, 4, 5 years respectively, same interest in all three cases.

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&.5>450 %d;W ghfq;fshf gphpf;f> mit KiwNa 3> 4> 5 Mz;Lfspy; 4> 5> kw;Wk; 6 rjtPjk; tl;b tpfpjj;jpy; rkkhd jdptl;b njhifia ju Ntz;Lk;. [GROUP I MAIN]

6. Rs. 21,765 are divided among three brothers A,B and C aged 17

years, 16 years and 15 years respectively in such a way that each receives the same amount at 5% p.a. S.I. when he reaches 18 years of age. Find the share of C. KiwNa 17> 16 kw;Wk; 15 tajhd %d;W rNfhjuh;fspilNa (A, B, C) &.21>765-I mth;fs; jdpj;jdpNa 18 taij milAk; nghOJ Mz;Lf;F 5 rjtPjk; jdptl;bapy; rkkhd njhifia milAkhW gphpj;jspf;fg;gLfpwJ. C-d; gq;if fzf;fpLf. [GROUP I MAIN]

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PROFIT & LOSS

1. 11 Ngdhf;fspd; mlf;ftpiy 10 Ngdhf;fspd; tpw;w tpiyf;F rkk; vdpy; ,yhg rjtPjk; The cost price of 11 pens is equal to the selling price of 10 pens. The profit per cent is Solution:

2. 8 nghUl;fspd; mlf;f tpiy 10 nghUl;fspd; tpw;Fk; tpiyf;F rkk;

vdpy; e~;l rjtPjk; The cost price of 8 articles is equal to the selling price of 10 articles. Then the percentage of loss is

Profit = S.P – C.P

Profit % = ( . . )

100.

S P C P

C P

Similarly Loss = C.P – S.P

Loss % = ( . . )

100.

C P S P

C P

If CP of x articles = SP of y articles. thq;fpa nghUl;fspd; x vz;zpf;if = tpw;w nghUl;fspd; y

vz;zpf;if

P% = 100x y

y

=

11 10100 10%

10

If CP of x articles = SP of y articles. thq;fpa nghUl;fspd; x vz;zpf;if = tpw;w nghUl;fspd; y

vz;zpf;if 2

% 1 0 0 1 0 0 2 0 %1 0

y xL

y

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3. A shopkeeper allows a discount of 10% to his customers and still gains 20%. Find the marked price of an article which costs Rs.450 to the shopkeeper. xU filf;fhuh; jd; thbf;ifahsh;fSf;F 10% js;Sgb je;Jk;>

20% ,yhgk; milfpd;whh;. xU nghUspd; cz;ik tpiy &.450 vdpy;> mg;nghUspd; Fwpj;j tpiyiaf; fhz;f.

WORKSHEET

1. By selling an article for Rs. 480, a person lost 20%. For what amount should be sell it to make profit of 20%?

xUth; xU nghUspid 480 &gha;f;F tpw;gid nra;jhy;> mtUf;F Vw;gLk; e~;lk; 20% mtUf;F 20% ,yhgk; fpilf;f Ntz;Lk; vd;why;> me;jg; nghUspid mth; vj;jid &gha;f;F tpw;f Ntz;Lk;?

Fwpj;j tpiy =100 %

100 %

yhgk;

m.tpjs;Sgb

Marked Price (100+Gain %)

M.P ×C.P.100-Discount %

= (100 20)

450(100 10)

= 120

450 .60090

Rs

20

2. Two-third of a consignment was sold at a profit of 5% and the remaining at a loss of 2%. If the total profit was Rs.400, then the value of the consignment was 2

3 gq;F rhkhd;fs; 5% ,yhgj;jpYk;> kPjp 2% el;lj;jpYk;

tpw;fg;gLfpd;wd. nkhj;j ,yhgk; &.400 vdpy;> nkhj;j rhkhd;fspd; kjpg;G

3. A person purchased a radio at 9/10 th of its selling price and sold it

at 8% more than its selling price. Then his gain per cent is xUth; xU thndhypg; ngl;bia mjd; tpw;gid tpiyapy; 9/10 klq;fpy; thq;fp mij tpw;gid tpiyia tpl 8% mjpfg;gLj;jp

tpw;whh;. vdpy; mth; ngw;w ,yhg rjtPjk;

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4. A man gains 20% by selling an article for a certain price. If he sells is at double the price, then percentage of profit will be: xU egh; xU nghUis xU Fwpg;gpl;l tpiyf;F tpw;gid nra;J 20 tpOf;fhL ,yhgk; ngWfpwhh;. mth; me;jg; nghUis ,uz;L klq;F tpiyf;F tpw;gid nra;jhy;> ,yhgk; vj;jid tpOf;fhlhf ,Uf;Fk;?

5. A sells a suitcase to B at 10% profit. B sells it to 30% profit. If C

pays ì 2860 for it, then the price at which A bought it is A xU #l;Nfir B ,lk; 10 tpOf;fhL ,yhgj;jpy; tpw;gid

nra;fpwhh;. B mjid 30 tpOf;fhL ,yhgj;jpw;F tpw;gid nra;fpwhh;.

mjw;fhf `2860I C nfhLf;fpwhh; vd;why;> me;jg; nghUis A vd;d tpiyf;F thq;fpapUg;ghh;?

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6. Rehaan purchased a bike for Rs.54,000. He sold it at a loss of 8 percent. With that money he again purchased another bike and sold it at a profit of 10 per cent. What is his overall loss/profit? Nu`hd; vd;gth; xU Nkhl;lhh;irf;fpis &.54>000-f;F thq;fpdhh;. gpwF mt;tz;bia 8 rjtPj e~;lj;jpy; tpw;whh;. mj;njhifia itj;J kw;nwhU Nkhl;lhh;irf;fpis thq;fp mjid 10 rjtPj yhgj;jpy; tpw;why; vdpy; nkhj;j yhg e~;lk; vt;tsT?

7. A dishonest merchant professes to sell his goods at cost price, but a

weight of 900 grams for one kg. What is his profit per cent? xU Neh;ikaw;w tzpfh; jd;Dila nghUl;fis mlf;f tpiyf;F tpw;gid nra;tjhff; $wpf; nfhs;fpwhh;. Mdhy; xU fpNyh vilf;Fg; gjpyhf 900 fpuhk; vilia msf;fpwhh;. mtUf;Ff; fpilf;Fk; ,yhgk; vj;jid tpOf;fhL?

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8. By selling 13 oranges for a rupee, a man loses 10%. How many should he sell for a rupee to gain 30%? xU egh; 13 MuQ;Rfis xU &gha;f;F tpw;gjd; thapyhf 10 rjtPjk; el;lj;ijr; re;jpf;fpwhh;. mth; 30 rjtPjk; ,yhgj;ijg; ngWtjw;F vj;jid MuQ;Rfis xU &gha;f;F tpw;gid nra;a Ntz;Lk;?

9. A merchant sells an item at 20% discount. There by gains 20% profit. If he won’t allowed any discount, what is his profit?.

xU tpahghhp xU nghUis 20 tpOf;fhL js;Sgbapy; tpw;gid nra;fpwhh;. ,jd; thapyhf mth; 20 tpOf;fhL ,yhgj;ijr; rk;ghjpf;fpwhh;. mth; ve;jj; js;SgbiaAk; toq;ftpy;iynadpy;> mtUila ,yhgk; vt;tsT?

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10. On an item a company gave 25% discount. Then they get 25%

profit of its gives 10% discount How much profit? xU epWtdk; xU nghUs;kPJ 25 tpOf;fhL js;Sgbia toq;FfpwJ. ,jd; thapyhf mth; 25 tpOf;fhL ,yhgj;ijr; rk;ghjpf;fpwhh;. me;j epWtdk; 10 tpOf;fhL js;Sgbia toq;fpdhy;> mtUila ,yhgk; vt;tsT?

25

11. A tradesman marks his goods at such a price that after allowing a discount of 15% he makes a profit of 20%. Find the marked price of an article which costs him Rs. 850?

xU th;j;jfh; jd;Dila nghUl;fis> 15 rjtPj js;Sgbia toq;fpa gpwF 20 rjtPj ,yhgk; ngWk; tifapy;> xU Fwpg;gpl;l tpiyf;F tpw;f epidf;fpwhh;. &.850 tpiyAs;s xU nghUis tpw;gid nra;tjw;F mth; eph;zapj;Js;s tpiy vd;d?

12. A television set was sold for Rs.14,400 after giving successive

discount of 10% and 20% respectively. What was the marked price? njhlh; js;Sgbfs; KiwNa 10%> 20% vd;wthW xU njhiyf;fhl;rpg; ngl;b &.14>400f;F tpw;fg;gl;lJ vdpy; mjd; Fwpj;j tpiy vd;d?

26

13. A man sells two articles for ì 5000 each neither losing nor gaining in the deal. If he sold one of them a gain of 25%, the other article is sold at a loss of xU egh; ,uz;L nghUl;fis me;jg; ghpth;j;jid thapyhf ,yhgNkh my;yJ el;lNkh vJTkpd;wp> xt;nthd;iwAk; `5000f;F tpw;gid nra;fpwhh;. mtw;Ws; xU nghUis mth; 25 tpOf;fhL ,yhgj;jpw;F tpw;wpUe;jhy;> ,uz;lhtJ nghUis vj;jid tpOf;fhL el;lj;jpw;F mth; tpw;wpUf;f Ntz;Lk;?

14. A merchant has 100 kg. of sugar, part of which he sells at 7%

profit and the rest at 17% profit. He gains 10% on the whole. Find how much he sold at 7% profit.

xU tpahghhp jd;dplKs;s 100 fpNyh rh;f;fiuapy; xU gFjpia 7% ,yhgj;jpw;Fk; kPjpia 17% ,yhgj;jpw;Fk; tpw;F nkhj;jj;jpy;

10% yhgk; mile;jhy; 7% ,yhgj;jpy; tpw;w rh;f;fiuapd; msT

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TNPSC GRP – I MAIN PREVIOUS YEAR QUESTIONS

1. A man sold two horses for Rs.990 each gaining 10% on the one and losing 10% on the other. Find his total gain or loss and also its percentage.(GRP – I MAIN: 8 MARKS) xUth; ,uz;L Fjpiufis jyh &.990-f;F tpw;wjpy;> xd;wpy; 10 rjtPjk; yhgKk; kw;wjpy; 10 rjtPjk; el;lKk; mile;jhh;. mtuJ nkhj;j yhgKk; my;yJ el;lj;ijAk; mjd; rjtPjj;ijAk; fzf;fpLf.

2. An item costing Rs. 200 is being sold at 10% loss. If the price is further reduced by 5%. What will be the selling price? &. 200 kjpg;Gs;s xU nghUs; 10% e~;lj;jpy; tpw;fg;gl;lJ. NkYk;

5% tpiy Fiwf;fg;gl;lhy;> mg;nghUs; (tpw;fg;gl;l) (m) tpw;w

tpiy vd;d? (GRP – I MAIN: 3 marks)

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3. A man buys oranges for Rs.x per dozen and sells them Rs. 10

x per

orange. What is his profit in Rs. Per orange? .(GRP – I MAIN: 3 marks) xUth; 1 l[d; MuQ;R &.x f;F thq;fp mjid &.

10

x xU MuQ;R

vd tpw;fpwhh;. mtUf;F fpilf;Fk; ,yhgk; (&.tpy;) xU MuQ;Rf;F vt;tsT?