Pamela has 30% as many marbles as Lynn. Lynn has 140% as many marbles as Betty. If Lynn gives 60 marbles to Betty, both will then have an equal number of marbles. Find the average number of marbles the three of them have.

Pamela	Lynn	Betty
3x7	10x7
	7x10	5x10
21 u	70 u	50 u

30% = ³⁰₁₀₀ = ³₁₀
140% = ¹⁴⁰₁₀₀= ⁷₅

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

	Lynn	Betty	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 Lynn and Betty have
= 70 u + 50 u
= 120 u

After Lynn gives to Betty, both of them will have the same number of marbles. 

The total number of marbles that Lynn and Betty have remains unchanged.

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

Number of marbles that Lynn gives to Betty
= 70 u - 60 u
= 10 u

10 u = 60

1 u = 60 ÷ 10 = 6

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 6
= 282

Answer(s): 282