Anna and Pamela collected postcards. Anna gave 30% of her postcards to Pamela and as a result, Pamela's postcards increased by 10%. If Anna had 63 postcards left, find the number of postcards Pamela should give to Anna in the end so that both had an equal number of postcards.

	Anna	Pamela	Comparing the change in Pamela's postcards
Before	10x1 = 10 u		10x3 = 30u
Change	- 3x1 = - 3 u	+ 3x1 = + 3 u	+ 1x3 = + 3 u
After	7x1 = 7 u		11x3 = 33 u

30% = ³⁰₁₀₀ = ³₁₀
10% = ¹⁰₁₀₀ = ¹₁₀

The increase in the number of postcards that Pamela had is repeated.  Make the increase in the number of postcards that Pamela had the same. LCM of 3 and 1 = 3

7 u = 63

1 u = 63 ÷ 7 = 9

Number of postcards that Pamela had more than Anna in the end
= 33 u - 7 u
= 26 u

Number of postcards that Pamela should give to Anna so that both had an equal number of postcards in the end
= 26 u ÷ 2
= 13 u
= 13 x 9
= 117

Answer(s): 117