Tank H contained 3 times as many guppies as Tank J. When 20% of the guppies in Tank H and 30% of the guppies in Tank J were transferred to Tank K, Tank K had 45 guppies, which was 25% more guppies than before. How many less guppies were there in Tank J than Tank H in the end?

	Tank H	Tank J	Tank K
Before	3 u	1 u	4x0.9 = 3.6 u
Change	- 0.6 u	- 0.3 u	+ 1x0.9 = + 0.9 u
After	2.4 u	0.7 u	5x0.9 = 4.5 u

Number of guppies that were transferred from Tank H to Tank K
= 20% x 3 u
= ²⁰₁₀₀ x 3 u
= 0.6 u

Number of guppies that were transferred from Tank J to Tank K
= 30% x 1 u
= ³⁰₁₀₀ x 1 u
= 0.3 u

25% = ²⁵₁₀₀ = ¹₄

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

Total number of guppies transferred from Tank H and Tank J into Tank K
= 0.6 u + 0.3 u
= 0.9 u

4.5 u = 45

1 u = 45 ÷ 4.5 = 10

Number of less guppies in Tank J than Tank H
= 2.4 u - 0.7 u
= 1.7 u
= 1.7 x 10
= 17

Answer(s): 17