Albert, David and Bobby had some marbles. David had 40% more marbles than Albert. David had ²₅ of Bobby's. After Albert gave 48 marbles to David, he had ¹₅ of what David had. How many more marbles did Bobby have than David in the end?

Albert	David	Bobby
5x2	7x2
	2x7	5x7
10	14	35

	Bobby	Albert	David	Total marbles of  Albert and David
Before	35x1 = 35 u	10x1 = 10 u	14x1 = 14 u	24x1 = 24 u
Change		- 48	+ 48
After	35 u	1x4 = 4 u	5x4 = 20 u	6x4 = 24 u

Number of marbles that David had more than Albert at first in percent
= 100%+ 40%
= 140%

140% = ¹⁴⁰₁₀₀ = ⁷₅

Albert : David = 5 : 7

The number of marbles that David had at first is repeated.  Make the number of marbles that David had at first the same.  LCM of 7 and 2 is 14.

When Albert gave 48 marbles to David, the total number of marbles that David and Albert had at first and in the end remains the same.  Make the total number of marbles that David and Albert had the same.  LCM of 24 and 6 is 24.

Number of marbles that Albert gave to David
= 10 u - 4 u
= 6 u

6 u = 48

1 u = 48 ÷ 6 = 8

Number of marbles that Bobby had more than David in the end
= 35 u - 20 u
= 15 u
= 15 x 8
= 120

Answer(s): 120