Question

A and B ran, at their respective constant rates, a race of 480 m. In the first heat, A gives B a head start of 48 m and beats him by 1/10th of a minute. In the second heat, A gives B a head start of 144 m and is beaten by 1/30th of a minute. What is B’s speed in m/s?
(A) 12
(B) 14
(C) 16
(D) 18
(E) 20

Answer 1

B's speed is 20 and A' speed  is 15

Answer 2

Given:

• A and B ran, at their respective constant rates, a race of 480 m.

ㅤ

• In the first heat, A gives B a head start of 48 m and beats him by 1/10th of a minute.

ㅤ

• In the second heat, A gives B a head start of 144 m and is beaten by 1/30th of a minute.

ㅤ

Find:

• What is B’s speed in m/s?

Calculations:

• (t + 1/10)
• (t - 1/30)

ㅤ

ㅤㅤ = 144 - 48

ㅤㅤ = 96 m

ㅤ

ㅤㅤ = 96/8

ㅤㅤㅤ= 12 m/s

ㅤ

Hence, 12 is the B's speed in m/s.