Jean and Winnie collected marbles. Jean gave 30% of her marbles to Winnie and as a result, Winnie's marbles increased by 10%. If Jean had 77 marbles left, find the number of marbles Winnie should give to Jean in the end so that both had an equal number of marbles.

	Jean	Winnie	Comparing the change in Winnie's marbles
Before	10x1 = 10 u		10x3 = 30u
Change	- 3x1 = - 3 u	+ 3x1 = + 3 u	+ 1x3 = + 3 u
After	7x1 = 7 u		11x3 = 33 u

30% = ³⁰₁₀₀ = ³₁₀
10% = ¹⁰₁₀₀ = ¹₁₀

The increase in the number of marbles that Winnie had is repeated.  Make the increase in the number of marbles that Winnie had the same. LCM of 3 and 1 = 3

7 u = 77

1 u = 77 ÷ 7 = 11

Number of marbles that Winnie had more than Jean in the end
= 33 u - 7 u
= 26 u

Number of marbles that Winnie should give to Jean so that both had an equal number of marbles in the end
= 26 u ÷ 2
= 13 u
= 13 x 11
= 143

Answer(s): 143