Linda and Yen collected marbles. Linda gave 30% of her marbles to Yen and as a result, Yen's marbles increased by 10%. If Linda had 28 marbles left, find the number of marbles Yen should give to Linda in the end so that both had an equal number of marbles.

	Linda	Yen	Comparing the change in Yen'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 Yen had is repeated.  Make the increase in the number of marbles that Yen had the same. LCM of 3 and 1 = 3

7 u = 28

1 u = 28 ÷ 7 = 4

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

Number of marbles that Yen should give to Linda so that both had an equal number of marbles in the end
= 26 u ÷ 2
= 13 u
= 13 x 4
= 52

Answer(s): 52