Julie and Erika collected seashells. Julie gave 30% of her seashells to Erika and as a result, Erika's seashells increased by 10%. If Julie had 70 seashells left, find the number of seashells Erika should give to Julie in the end so that both had an equal number of seashells.

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

7 u = 70

1 u = 70 ÷ 7 = 10

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

Number of seashells that Erika should give to Julie so that both had an equal number of seashells in the end
= 26 u ÷ 2
= 13 u
= 13 x 10
= 130

Answer(s): 130