Seth, Will and Harry had some balls. Will had 20% less balls than Seth. Will had ³₇ of Harry's. After Seth gave 54 balls to Will, he had ¹₂ of what Will had. How many more balls did Harry have than Seth in the end?

Seth	Will	Harry
5x3	4x3
	3x4	7x4
15	12	28

	Harry	Seth	Will	Total balls of  Seth and Will
Before	28x1 = 28 u	15x1 = 15 u	12x1 = 12 u	27x1 = 27 u
Change		- 54	+ 54
After	28 u	1x9 = 9 u	2x9 = 18 u	3x9 = 27 u

Number of balls that Will had less than Seth at first in percent
= 100% - 20%
= 80%

80% = ⁸⁰₁₀₀ = ⁴₅

Seth : Will = 5 : 4

The number of balls that Will had at first is repeated.  Make the number of balls that Will had at first the same.  LCM of 4 and 3 is 12.

When Seth gave 54 balls to Will, the total number of balls that Will and Seth had at first and in the end remains the same.  Make the total number of balls that Will and Seth had the same.  LCM of 27 and 3 is 27.

Number of balls that Seth gave to Will
= 15 u - 9 u
= 6 u

6 u = 54

1 u = 54 ÷ 6 = 9

Number of balls that Harry had more than Seth in the end
= 28 u - 9 u
= 19 u
= 19 x 9
= 171

Answer(s): 171