Olivia and Marion collected marbles. Olivia gave 30% of her marbles to Marion and as a result, Marion's marbles increased by 10%. If Olivia had 35 marbles left, find the number of marbles Marion should give to Olivia in the end so that both had an equal number of marbles.

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

7 u = 35

1 u = 35 ÷ 7 = 5

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

Number of marbles that Marion should give to Olivia so that both had an equal number of marbles in the end
= 26 u ÷ 2
= 13 u
= 13 x 5
= 65

Answer(s): 65