two boys are 15 miles apart...

Question

two boys are 15 miles apart. If they walk towards each other they meet in 3 hours. If they both walk in the same direction on boy overtakes the other on 8 hours. How fast does each boy walk?

Answer 1

15 = r1*3 + r2*3 ---> 5 = r1 + r2 = r2 + r1



15 + r1*8 = r2*8

15 = 8(r2 - r1)

15/8 = r2 - r1

15/8 + 5 = 2*r2

15/8 + 40/8 = 2 * r2

55/8 = 2 * r2

r2 = 55/16 = 3 and 7/16 mph

r1 = 1 and 9/16 = 25/16 mph

In 8 hours, the slower boy goes 25/2 = 12.5 miles
while the faster boy goes 55/2 = 27.5 miles = 12.5 + 15 miles.