Tank Q contained 2 times as many guppies as Tank R. When 30% of the guppies in Tank Q and 30% of the guppies in Tank R were transferred to Tank S, Tank S had 54 guppies, which was 20% more guppies than before. How many more guppies were there in Tank S than Tank R in the end?

	Tank Q	Tank R	Tank S
Before	2 u	1 u	5x0.9 = 4.5 u
Change	- 0.6 u	- 0.3 u	+ 1x0.9 = + 0.9 u
After	1.4 u	0.7 u	6x0.9 = 5.4 u

Number of guppies that were transferred from Tank Q to Tank S
= 30% x 2 u
= ³⁰₁₀₀ x 2 u
= 0.6 u

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

20% = ²⁰₁₀₀ = ¹₅

Some guppies from Tank Q and Tank R were transferred to Tank S.  The total number of guppies transferred from Tank Q and Tank R into Tank S is the same.

Total number of guppies transferred from Tank Q and Tank R into Tank S
= 0.6 u + 0.3 u
= 0.9 u

5.4 u = 54

1 u = 54 ÷ 5.4 = 10

Number of more guppies in Tank S than Tank R
= 5.4 u - 0.7 u
= 4.7 u
= 4.7 x 10
= 47

Answer(s): 47