Question

Two race cars, Car X and Y, are at the starting point of a 2km track at the same time. Car X and Car Y make one lap every 60s and every 80s respectively. How long, in minutes, will it take for the faster car to be 5 laps ahead of the slower car?

Answer 1

Answer:

It will take the faster car 15 minutes to be 5 laps ahead of the slower car.

Step-by-step explanation:

Car X is faster than Car Y.

Car X makes 1 lap in 60 seconds.

Car Y makes 1 lap in 80 second.

This means Car X is 20 seconds faster than Car Y.

It also mean that Car X needs only three 20 seconds to be 1 lap ahead of Car Y. But Car X can only accumulate 60 seconds after 3 laps.

So, Car X is 1 lap ahead after every 3 laps.

Car X will be 5 laps ahead by (3×5)th lap or 15th lap.

It will take Car X (15 × 60) seconds to be 5 laps ahead of Car Y.

15 × 60 = 900 seconds

900 seconds = 900/60 minutes

= 15 minutes.