time & work & time & distance in quantitative aptitude
Post on 18-Dec-2014
5.794 Views
Preview:
DESCRIPTION
TRANSCRIPT
5 DECEMBER 09 www.afterschoool.tk 1
Time & Work & Time & Distance in Quantitative Aptitude
by :
DR. T.K. JAIN
AFTERSCHO☺OL
centre for social entrepreneurship
sivakamu veterinary hospital road
bikaner 334001 rajasthan, india
www.afterschoool.tk
mobile : 91+9414430763
5 DECEMBER 09 www.afterschoool.tk 2
10 people working 8 hours a day complete a work in 24 days. How many persons will be
required to complete the work in 16 days working 10 hours a day?
= 10 * 8/10* 24/16
=12 persons
5 DECEMBER 09 www.afterschoool.tk 3
10men+6boys=20days, 12m+4boys=18days, in what time
will 8m+8b do the work?
12m+4b=1/18
10m+6b=1/20
solving it we get: m=240, b=720
thus 8men + 8boys will do it in 22.5 days
5 DECEMBER 09 www.afterschoool.tk 4
3300 men have provision for 32 days if 850 gram per head. After 7
days X more persons came and now the provision will last for 8days less if given 825 gm per
head. What is X?Total = 3300*32*.85=89760
7 days=19635,left= 70125=
70125/(17*.825)=5000
X=1700 ans.
5 DECEMBER 09 www.afterschoool.tk 5
A can do in 12 and B in 15 days, if they work together, how many
days are required?
1/12+1/15 = 27/180
reverse it = 6.67 days.
5 DECEMBER 09 www.afterschoool.tk 6
A+B can do a work in 10 days, A can do it in 15 days. In how many
days B alone can do the work?
1/10 – 1/15
= 5/150
=1/30 or 30 days are required by B
5 DECEMBER 09 www.afterschoool.tk 7
A and B can do a job in X days. A alone take 8 days more than X and B can take 18 days more than X,
what is X?
Formula = sqrt (8 *18)
= 12 Answer
5 DECEMBER 09 www.afterschoool.tk 8
A works twice as fast as B. If B can do it in 12 days, how many
days are required by A+B?
1/6 +1/12 = ¼
= 4 days
5 DECEMBER 09 www.afterschoool.tk 9
A is thrice as good as B and can do a work in 60 days less than B. In how many days can they do it
together?
1/30 + 1/90 = 4/90
= 22.5 days.
5 DECEMBER 09 www.afterschoool.tk 10
A can do it in 25 days, B in 20 days. They work together for 5 days. A leaves. How much time
more is required?
Work done by A = 5/25 = 1/5
B has to do 4/5 , 20*4/5 =16
B has worked for 5 days, so 11 more days are required.
5 DECEMBER 09 www.afterschoool.tk 11
A moves @ 90 KM per hour from X to Y. Returns from Y to X @ 60 KM per hour. He agains goes to Y @ 30 KM per hour. What is
his average speed?
1/3(1/90+1/60+1/30)
=49
or assume distance between X and Y 180, total time = 2+3+6 = 540/11 = 49
5 DECEMBER 09 www.afterschoool.tk 12
X travels from A to B and Y start from B to A. X travels at 75 km
per hour. They finish the remaining journey after cross over in 2.66 and 3 hours respectively.
What is the speed of Y? Ratio of speed = opposite ratio of sq. Root of
remaining time
75:X = sqrt(3): Sqrt(2.66)
X = (75 * 1.63) / 1.73) = 70 km
5 DECEMBER 09 www.afterschoool.tk 13
Theif run 50 km from police. Speed of theif is 60 km, what
should be the minimum speed of police to catch them before next
120 KM?
=(50)/(X-60)=2
2X-120=50
X=170 or X = 85 Ans.
5 DECEMBER 09 www.afterschoool.tk 14
thanks....
Join, promote and establish afterschoool network
afterschoool@in.com
your partners in social entrepreneurship....
top related