Question

37.

Answer 1

Answer:

60 km/hr

Step-by-step explanation:

Let the speed at the initial average speed from Town X to Town Y be a.

We are told that it journeyed to Town Z at an average speed 20 km/h faster than its initial average speed. Thus, its average speed here is (a + 20) km/hr.

Town Y was 200 km from Town Z.

Thus, time spent here is;

t_2 = 200/(a + 20)

Time from X to Y is; t_1 = 150/a

We are told that it took the same time to travel for both parts of the journey.

Thus; t_1 = t_2

150/a = 200/(a + 20)

Cross multiply to get;

150(a + 20) = 200a

150a + 3000 = 200a

200a - 150a = 3000

50a = 3000

a = 3000/50

a = 60 km/hr