Oliver and Sean had 158 marbles in total. Sean had 88 marbles more than Oliver at first. After Oliver and Sean played a game with Usha, Oliver had ³₁₁ as many marbles as Sean. If Oliver lost as many marbles as Sean to Usha, find the number of marbles that Oliver lost to Usha.

	Oliver	Sean	Difference
Before	1 u	1 u + 88	88
Change	- ?	- ?
After	3 p	11 p	8 p

Total number of marbles at first
= 1 u + 1 u + 88 
= 2 u + 88

2 u + 88 = 158
2 u = 158 - 88
2 u = 70

1 u = 70 ÷ 2 = 35

Since Oliver lost the same number of marbles as Sean, the difference in the number of marbles between Oliver and Sean at first and in the end remains the same.

Difference in the number of marbles in the end
= 11 p - 3 p
= 8 p

8 p = 88

1 p = 88 ÷ 8 = 11

Number of marbles that Oliver lost to Usha
= 1 u - 3 p
= 35 - 3 x 11
= 35 - 33
= 2

Answer(s): 2