Tammy has 30% as many marbles as Joelle. Joelle has 110% as many marbles as Usha. If Joelle gives 55 marbles to Usha, both will then have an equal number of marbles. Find the average number of marbles the three of them have.

Tammy	Joelle	Usha
3x11	10x11
	11x10	10x10
33 u	110 u	100 u

30% = ³⁰₁₀₀ = ³₁₀
110% = ¹¹⁰₁₀₀= ¹¹₁₀

The number of marbles that Tammy has is repeated.  Make the number of marbles that Tammy has the same. LCM of 10 and 11 is 110.

	Joelle	Usha	Total
Before	110 u	100 u	210 u
Change	- 5 u	+ 5 u
After	105 u	105 u	210 u

Total number of marbles that Joelle and Usha have
= 110 u + 100 u
= 210 u

After Joelle gives to Usha, both of them will have the same number of marbles. 

The total number of marbles that Joelle and Usha have remains unchanged.

Number of marbles that each of them will have
= 210 u ÷ 2
= 105 u

Number of marbles that Joelle gives to Usha
= 110 u - 105 u
= 5 u

5 u = 55

1 u = 55 ÷ 5 = 11

Total number of marbles that three of them have
= 210 u + 33 u
= 243 u

Average number of marbles that each of them have
= 243 u ÷ 3
= 81 u
= 81 x 11
= 891

Answer(s): 891