Jaslyn has 30% as many marbles as Diana. Diana has 140% as many marbles as Pamela. If Diana gives 120 marbles to Pamela, both will then have an equal number of marbles. Find the average number of marbles the three of them have.

Jaslyn	Diana	Pamela
3x7	10x7
	7x10	5x10
21 u	70 u	50 u

30% = ³⁰₁₀₀ = ³₁₀
140% = ¹⁴⁰₁₀₀= ⁷₅

The number of marbles that Jaslyn has is repeated.  Make the number of marbles that Jaslyn has the same. LCM of 10 and 7 is 70.

	Diana	Pamela	Total
Before	70 u	50 u	120 u
Change	- 10 u	+ 10 u
After	60 u	60 u	120 u

Total number of marbles that Diana and Pamela have
= 70 u + 50 u
= 120 u

After Diana gives to Pamela, both of them will have the same number of marbles. 

The total number of marbles that Diana and Pamela have remains unchanged.

Number of marbles that each of them will have
= 120 u ÷ 2
= 60 u

Number of marbles that Diana gives to Pamela
= 70 u - 60 u
= 10 u

10 u = 120

1 u = 120 ÷ 10 = 12

Total number of marbles that three of them have
= 120 u + 21 u
= 141 u

Average number of marbles that each of them have
= 141 u ÷ 3
= 47 u
= 47 x 12
= 564

Answer(s): 564