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

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

7 u = 28

1 u = 28 ÷ 7 = 4

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

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

Answer(s): 52