Graphical Approach to solve multi-stepproblems
T. T. Liang, Brain Maths, Vol. 2, problem 44
The railway distance between town X and Y is 680 km. A train traveling at 75 km/hr leaves town X heading for town Y. At the same time, a second train traveling at 95 km/hr leaves town Y heading for town X. How far apart are the trains 1 hour before they meet?
Graphical Approach to solve multi-stepproblems
The railway distance between town X and Y is 680 km. A train traveling at 75 km/hr leaves town X heading for town Y. At the same time, a second train traveling at 95 km/hr leaves town Y heading for town X. How far apart are the trains 1 hour before they meet?
X
Y
680 km
75 km/hr
95 km/hr
Graphical Approach to solve multi-stepproblems
How far apart are the trains 1 hour before they meet?
?
Graphical Approach to solve multi-stepproblems
Distance: 680 kmSpeed: Train leaving town X: 75 km/hr Train leaving town Y: 95 km/hr
Determine 1) When the trains meet,2) Where they are 1 hr before they meet.
Graphical Approach to solve multi-stepproblems
Distance: 680 kmSpeed: Train leaving town X: 75 km/hr Train leaving town Y: 95 km/hr
680 km
Graphical Approach to solve multi-stepproblems
Distance: 680 kmSpeed: Train leaving town X: 75 km/hr Train leaving town Y: 95 km/hr
T: Time when the trains meet
680 km
75 km/hr T 95 km/hr T
Graphical Approach to solve multi-stepproblems
680 km
75 km/hr T 95 km/hr T
Graphical Approach to solve multi-stepproblems
680 km
75 km/hr T 95 km/hr T
680 km = 170 km/hr T
Trains meet 4 hrs after they depart.
T = 4 hrs
Graphical Approach to solve multi-stepproblems
680 km
75 km/hr T 95 km/hr T
Trains meet 4 hrs after they depart.
What is the distance between the trains1 hour before they meet?
?75 km 75 km 75 km 95 km95 km95 km
3 hours 3 hours
Graphical Approach to solve multi-stepproblems
680 km
75 km/hr T 95 km/hr T
What is the distance between the trains1 hour before they meet?
75 km 75 km 75 km 95 km95 km95 km ? 170 km3 hours 3 hours
Graphical Approach to solve multi-stepproblems
680 km
75 km/hr T 95 km/hr T
What is the distance between the trains1 hour before they meet?
75 km 75 km 75 km 95 km95 km95 km 170 km
170 km