Nora and Betty collected seashells. Nora gave 60% of her seashells to Betty and as a result, Betty's seashells increased by 20%. If Nora had 16 seashells left, find the number of seashells Betty should give to Nora in the end so that both had an equal number of seashells.

	Nora	Betty	Comparing the change in Betty's seashells
Before	5x1 = 5 u		5x3 = 15u
Change	- 3x1 = - 3 u	+ 3x1 = + 3 u	+ 1x3 = + 3 u
After	2x1 = 2 u		6x3 = 18 u

60% = ⁶⁰₁₀₀ = ³₅
20% = ²⁰₁₀₀ = ¹₅

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

2 u = 16

1 u = 16 ÷ 2 = 8

Number of seashells that Betty had more than Nora in the end
= 18 u - 2 u
= 16 u

Number of seashells that Betty should give to Nora so that both had an equal number of seashells in the end
= 16 u ÷ 2
= 8 u
= 8 x 8
= 64

Answer(s): 64