Vanessa and Hilda collected seashells. Vanessa gave 30% of her seashells to Hilda and as a result, Hilda's seashells increased by 10%. If Vanessa had 42 seashells left, find the number of seashells Hilda should give to Vanessa in the end so that both had an equal number of seashells.

	Vanessa	Hilda	Comparing the change in Hilda's seashells
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 seashells that Hilda had is repeated.  Make the increase in the number of seashells that Hilda had the same. LCM of 3 and 1 = 3

7 u = 42

1 u = 42 ÷ 7 = 6

Number of seashells that Hilda had more than Vanessa in the end
= 33 u - 7 u
= 26 u

Number of seashells that Hilda should give to Vanessa so that both had an equal number of seashells in the end
= 26 u ÷ 2
= 13 u
= 13 x 6
= 78

Answer(s): 78