Tank J contained 2 times as many guppies as Tank K. When 40% of the guppies in Tank J and 40% of the guppies in Tank K were transferred to Tank L, Tank L had 216 guppies, which was 20% more guppies than before. How many more guppies were there in Tank L than Tank K in the end?

	Tank J	Tank K	Tank L
Before	2 u	1 u	5x1.2 = 6 u
Change	- 0.8 u	- 0.4 u	+ 1x1.2 = + 1.2 u
After	1.2 u	0.6 u	6x1.2 = 7.2 u

Number of guppies that were transferred from Tank J to Tank L
= 40% x 2 u
= ⁴⁰₁₀₀ x 2 u
= 0.8 u

Number of guppies that were transferred from Tank K to Tank L
= 40% x 1 u
= ⁴⁰₁₀₀ x 1 u
= 0.4 u

20% = ²⁰₁₀₀ = ¹₅

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

Total number of guppies transferred from Tank J and Tank K into Tank L
= 0.8 u + 0.4 u
= 1.2 u

7.2 u = 216

1 u = 216 ÷ 7.2 = 30

Number of more guppies in Tank L than Tank K
= 7.2 u - 0.6 u
= 6.6 u
= 6.6 x 30
= 198

Answer(s): 198