Tank K contained 4 times as many guppies as Tank L. When 20% of the guppies in Tank K and 20% of the guppies in Tank L were transferred to Tank M, Tank M had 120 guppies, which was 50% more guppies than before. How many more guppies were there in Tank M than Tank L in the end?

	Tank K	Tank L	Tank M
Before	4 u	1 u	2x1 = 2 u
Change	- 0.8 u	- 0.2 u	+ 1x1 = + 1 u
After	3.2 u	0.8 u	3x1 = 3 u

Number of guppies that were transferred from Tank K to Tank M
= 20% x 4 u
= ²⁰₁₀₀ x 4 u
= 0.8 u

Number of guppies that were transferred from Tank L to Tank M
= 20% x 1 u
= ²⁰₁₀₀ x 1 u
= 0.2 u

50% = ⁵⁰₁₀₀ = ¹₂

Some guppies from Tank K and Tank L were transferred to Tank M.  The total number of guppies transferred from Tank K and Tank L into Tank M is the same.

Total number of guppies transferred from Tank K and Tank L into Tank M
= 0.8 u + 0.2 u
= 1 u

3 u = 120

1 u = 120 ÷ 3 = 40

Number of more guppies in Tank M than Tank L
= 3 u - 0.8 u
= 2.2 u
= 2.2 x 40
= 88

Answer(s): 88