Yen and Elyse collected seashells. Yen gave 30% of her seashells to Elyse and as a result, Elyse's seashells increased by 25%. If Yen had 42 seashells left, find the number of seashells Elyse should give to Yen in the end so that both had an equal number of seashells.

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

7 u = 42

1 u = 42 ÷ 7 = 6

Number of seashells that Elyse had more than Yen in the end
= 15 u - 7 u
= 8 u

Number of seashells that Elyse should give to Yen so that both had an equal number of seashells in the end
= 8 u ÷ 2
= 4 u
= 4 x 6
= 24

Answer(s): 24