Mary has 25% as many marbles as Olivia. Olivia has 130% as many marbles as Linda. If Olivia gives 18 marbles to Linda, both will then have an equal number of marbles. Find the average number of marbles the three of them have.

Mary	Olivia	Linda
1x13	4x13
	13x4	10x4
13 u	52 u	40 u

25% = ²⁵₁₀₀ = ¹₄
130% = ¹³⁰₁₀₀= ¹³₁₀

The number of marbles that Mary has is repeated.  Make the number of marbles that Mary has the same. LCM of 4 and 13 is 52.

	Olivia	Linda	Total
Before	52 u	40 u	92 u
Change	- 6 u	+ 6 u
After	46 u	46 u	92 u

Total number of marbles that Olivia and Linda have
= 52 u + 40 u
= 92 u

After Olivia gives to Linda, both of them will have the same number of marbles. 

The total number of marbles that Olivia and Linda have remains unchanged.

Number of marbles that each of them will have
= 92 u ÷ 2
= 46 u

Number of marbles that Olivia gives to Linda
= 52 u - 46 u
= 6 u

6 u = 18

1 u = 18 ÷ 6 = 3

Total number of marbles that three of them have
= 92 u + 13 u
= 105 u

Average number of marbles that each of them have
= 105 u ÷ 3
= 35 u
= 35 x 3
= 105

Answer(s): 105