Question

If Harry can rake the leaves 8 times faster than his brother, and if they work together they will take 3 hours to complete the job, how long does Jimmy take to rake the leaves of a yard? a) 2 hours b) 4 hours c) 6 hours d) 12 hours

Answer 1

1/x + 1/(8x) = 1/3

8 + 1 = 8x/3

8x/3 = 9

x = 9(3/8) = 27/8 = 3 3/8 hours

Working alone:

Jerry--3 3/8 hours

Harry--27 hours