Since Mr. Williiams travels at 30 mph, in after time t (in hours) have elapsed, he will have traveled the distance d

d = 30t

Mr. Speedster starts out at the same point 4 hours later at 60 mph. So after time t have elapsed ** since Mr. Speedster started, **he will have traveled for t - 4 hours and covered the distance 60(t-4).

At the time t when Mr. Speedster overtakes Mr. Williams, they will have traveled the same distance d:

d = 30t = 60(t - 4)

Solve this equation for t:

30 t = 60t - 240

-30t =-240

t = 8

8 hours have elapsed since Mr. Williams started traveling, so 8 - 4 = 4 hours have elapsed since Mr. Speedster started traveling.

**Mr. Speedster will overtake Mr. Williams in 4 hours.**

This means Mr. Speedster will overtake Mr. Williams in 8 hours after

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