Question

Mandy begins bicycling West at 30 miles per hour at 11:00 am. If Liz leaves from the same point 20 minutes later bicycling West at 36 miles per hour, when will she catch Mandy?
A. 2:00 pm
B. 1:00 pm
C. 1:30 pm
D. 2:30 pm

Answer 1

36(t - 1/3) = 30t

36t - 12 = 30t

6t = 12

t = 2

2 hours past 11AM is 1PM. So Liz catches

Mandy at 1PM.