Tiffany has 30% as many stamps as Ivory. Ivory has 110% as many stamps as Gwen. If Ivory gives 45 stamps to Gwen, both will then have an equal number of stamps. Find the average number of stamps the three of them have.

Tiffany	Ivory	Gwen
3x11	10x11
	11x10	10x10
33 u	110 u	100 u

30% = ³⁰₁₀₀ = ³₁₀
110% = ¹¹⁰₁₀₀= ¹¹₁₀

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

	Ivory	Gwen	Total
Before	110 u	100 u	210 u
Change	- 5 u	+ 5 u
After	105 u	105 u	210 u

Total number of stamps that Ivory and Gwen have
= 110 u + 100 u
= 210 u

After Ivory gives to Gwen, both of them will have the same number of stamps. 

The total number of stamps that Ivory and Gwen have remains unchanged.

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

Number of stamps that Ivory gives to Gwen
= 110 u - 105 u
= 5 u

5 u = 45

1 u = 45 ÷ 5 = 9

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

Average number of stamps that each of them have
= 243 u ÷ 3
= 81 u
= 81 x 9
= 729

Answer(s): 729