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?
+66 (1/2.5h)x+(1/1.5h)x=1
x=0.9375
24/0.9375= 25.6
They will pass each other 25 times
+128408 THX, BF !!!!
Here's another way to see this
Let the circumference of the Earth = C
So every hour Superman covers C / 2.5 = C /( 5/2) = (2/5)C
And every hour Fals covers C /(1/5) = C / (3/2) = (2/3)C
So...every hour they cover (2/5 + 2/3) C = (16/15)C
Which means that it takes them (15/16) hrs to meet every time
So...the number of times they meet in 24 hrs = 24 / (15/16) ≈ 25.6 times ≈ 25 times
