Question

15. A is faster than B. A and B each walk 20 km. The sum
of their speeds is 9 km/h and the sum of times taken
by them is 9h. Then, A's speed is equal to
(a) 5 km/h
(b) 3 km/h
(c) 6 km/h
(d) 4 km/h​

Answer 1

Step-by-step explanation:

Let the speed of A be x.

Sum of the speeds of A and B is 9kmph

Then speed of be= 9-x

Distance=20 km

Time taken by A = distance/speed =20/x

Time taken by B = distance/speed = 20/9-x

Sum of their times = 9

20/x +20/9-x =9

x=4 kmph

Therefore speed of A is 4kmph