Question

22. A and B travels opposite to their respective destination with 60km/hr speed and 40km/hr
speed respectively. After 23400s what will be the distance between A and B?
A. 130Km
B. 650Km *
C 7800Km
D. 39000Km

Answer 1

Let distance from A to B=x km= distance from B to A.

$Time \: taken \: by \: train \: from \: A \: to \: B \:  = \:   = \binom{x}{60}$

$Time \: taken \: by \: train  \: from \: B \: to \: A = \binom{x}{80}$

Total time taken by train

$= \binom{x}{60} + \binom{x}{80} = \binom{2x}{7x} by \: 240 \: hr$

average speed=

total time

___________

total distance

$\binom{2x}{7x} \: by \: 240 = \binom{480}{7} \: km \: {h}^{ - 1}$

answer is 480/7