A and B take part in a 100 m race. A gives B a start of 10 m and still beats B by 5 seconds. If A's speed is 2.5 m/s, find B's speed.
A
2 m/s
B
2.5 m/s
C
1.5 m/s
D
2.25 m/s
Correct Option - A
Explaination
Time taken by A to cover 100 m
= 100/2.5
= 40 seconds
A gives B a start of 10 m. Hence, B covers only 90 m.
A beats B by 5 seconds.
Hence, time taken by B to cover 90 m
= 40+5
= 45 seconds
B covers 90 m in 45 seconds.
B's speed
= 90/45
= 2 m/s