Opal and Vanessa collected stamps. Opal gave 30% of her stamps to Vanessa and as a result, Vanessa's stamps increased by 25%. If Opal had 63 stamps left, find the number of stamps Vanessa should give to Opal in the end so that both had an equal number of stamps.

	Opal	Vanessa	Comparing the change in Vanessa's stamps
Before	10x1 = 10 u		4x3 = 12u
Change	- 3x1 = - 3 u	+ 3x1 = + 3 u	+ 1x3 = + 3 u
After	7x1 = 7 u		5x3 = 15 u

30% = ³⁰₁₀₀ = ³₁₀
25% = ²⁵₁₀₀ = ¹₄

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

7 u = 63

1 u = 63 ÷ 7 = 9

Number of stamps that Vanessa had more than Opal in the end
= 15 u - 7 u
= 8 u

Number of stamps that Vanessa should give to Opal so that both had an equal number of stamps in the end
= 8 u ÷ 2
= 4 u
= 4 x 9
= 36

Answer(s): 36