Eva and Linda collected seashells. Eva gave 25% of her seashells to Linda and as a result, Linda's seashells increased by 30%. If Eva had 81 seashells left, find the number of seashells Linda should give to Eva in the end so that both had an equal number of seashells.

	Eva	Linda	Comparing the change in Linda's seashells
Before	4x3 = 12 u		10x1 = 10u
Change	- 1x3 = - 3 u	+ 1x3 = + 3 u	+ 3x1 = + 3 u
After	3x3 = 9 u		13x1 = 13 u

25% = ²⁵₁₀₀ = ¹₄
30% = ³⁰₁₀₀ = ³₁₀

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

9 u = 81

1 u = 81 ÷ 9 = 9

Number of seashells that Linda had more than Eva in the end
= 13 u - 9 u
= 4 u

Number of seashells that Linda should give to Eva so that both had an equal number of seashells in the end
= 4 u ÷ 2
= 2 u
= 2 x 9
= 18

Answer(s): 18