Emma and Anna collected seashells. Emma gave 30% of her seashells to Anna and as a result, Anna's seashells increased by 10%. If Emma had 77 seashells left, find the number of seashells Anna should give to Emma in the end so that both had an equal number of seashells.

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

7 u = 77

1 u = 77 ÷ 7 = 11

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

Number of seashells that Anna should give to Emma so that both had an equal number of seashells in the end
= 26 u ÷ 2
= 13 u
= 13 x 11
= 143

Answer(s): 143