Math
posted by Ephraim on .
Pete and jan compete as a team in a biathlon. Pete runs at a speed of 9 km/ h for x hours. Jan cycles at twice Pete's running speed for 1 hour and 30 minutes. The total distance of the biathlon is 42 km. Find, in hour and minutes, Pete's running time.

Distance = Rate * Time or D = RT
for Pete : D = 9x
for Jan : D = 18(1.5)
so 9x + 18(1.5) = 42
solve for x
(I got 1 hour, 40 minutes)