Eva and Lucy collected seashells. Eva gave 50% of her seashells to Lucy and as a result, Lucy's seashells increased by 30%. If Eva had 18 seashells left, find the number of seashells Lucy should give to Eva in the end so that both had an equal number of seashells.

	Eva	Lucy	Comparing the change in Lucy's seashells
Before	2x3 = 6 u		10x1 = 10u
Change	- 1x3 = - 3 u	+ 1x3 = + 3 u	+ 3x1 = + 3 u
After	1x3 = 3 u		13x1 = 13 u

50% = ⁵⁰₁₀₀ = ¹₂
30% = ³⁰₁₀₀ = ³₁₀

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

3 u = 18

1 u = 18 ÷ 3 = 6

Number of seashells that Lucy had more than Eva in the end
= 13 u - 3 u
= 10 u

Number of seashells that Lucy should give to Eva so that both had an equal number of seashells in the end
= 10 u ÷ 2
= 5 u
= 5 x 6
= 30

Answer(s): 30