Tank K contained 3 times as many guppies as Tank L. When 50% of the guppies in Tank K and 10% of the guppies in Tank L were transferred to Tank M, Tank M had 160 guppies, which was 25% 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	3 u	1 u	4x1.6 = 6.4 u
Change	- 1.5 u	- 0.1 u	+ 1x1.6 = + 1.6 u
After	1.5 u	0.9 u	5x1.6 = 8 u

Number of guppies that were transferred from Tank K to Tank M
= 50% x 3 u
= ⁵⁰₁₀₀ x 3 u
= 1.5 u

Number of guppies that were transferred from Tank L to Tank M
= 10% x 1 u
= ¹⁰₁₀₀ x 1 u
= 0.1 u

25% = ²⁵₁₀₀ = ¹₄

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
= 1.5 u + 0.1 u
= 1.6 u

8 u = 160

1 u = 160 ÷ 8 = 20

Number of more guppies in Tank M than Tank L
= 8 u - 0.9 u
= 7.1 u
= 7.1 x 20
= 142

Answer(s): 142