Question

In a race of 100 ft, Kim took 10 seconds, and Jim took 11 seconds. In the second race of 500 ft, Kim and Jim travel with their respective original speeds. By how much time will Kim beat Jim?

• A. 5 seconds
• B. 7 seconds
• C. 4 seconds
• D. 6 seconds

Answer 1

The correct option is A 5 seconds

Using the formula:
$Speed=\frac{\text{Distance}}{\text{Time}}$

$SpeedofKim=\frac{\text{100}}{10}$
$=10ft/s$

$SpeedofJim=\frac{\text{100}}{11}m/s$

In second race of 500 ft,

Using the formula:
$Time=\frac{\text{Distance}}{\text{Speed}}$

$TimetakenbyKim=\frac{\text{500}}{10}$
$=50seconds$

$TimetakenbyJim=\frac{\text{500}}{100/11}$

$=\frac{500\times 11}{100}$

$=5\times 11=55seconds$

$\therefore$ Kim beats Jim by 5 seconds.