Superman and flash are running around the world in opposite directions. Superman can go around the world in 2.5 hours, and Flash can do the same in 1.5 hours. Assuming they start at the same time and place, how many times will they pass each other going in opposite directions in a 24 hour period?

Question

I don't know what to do so I tried to calculate when they meet first:
speed superman=1world/2.5h
speed flash=1world/1.5h

they meet when it equals 1 world we add their distances
we know they start at the same time. x is the time that passed til they meet.
(1world/2.5h)x+(1world/1.5h)x=1world
x(4world/3.75h)=1world
x=0.9375h

I dont know how to continue.

Answer 1

You correctly calculated that the pass each other every 15/16 of an hour
so, what is 24 ÷ 15/16 ?

Answer 2

it gives 25.6. does it mean they pass each other 25 times?