Kathy and Sabrina collected seashells. Kathy gave 30% of her seashells to Sabrina and as a result, Sabrina's seashells increased by 10%. If Kathy had 56 seashells left, find the number of seashells Sabrina should give to Kathy in the end so that both had an equal number of seashells.

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

7 u = 56

1 u = 56 ÷ 7 = 8

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

Number of seashells that Sabrina should give to Kathy so that both had an equal number of seashells in the end
= 26 u ÷ 2
= 13 u
= 13 x 8
= 104

Answer(s): 104