Tank X contained 2 times as many guppies as Tank Y. When 30% of the guppies in Tank X and 40% of the guppies in Tank Y were transferred to Tank Z, Tank Z had 60 guppies, which was 50% more guppies than before. How many more guppies were there in Tank Z than Tank Y in the end?

	Tank X	Tank Y	Tank Z
Before	2 u	1 u	2x1 = 2 u
Change	- 0.6 u	- 0.4 u	+ 1x1 = + 1 u
After	1.4 u	0.6 u	3x1 = 3 u

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

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

50% = ⁵⁰₁₀₀ = ¹₂

Some guppies from Tank X and Tank Y were transferred to Tank Z.  The total number of guppies transferred from Tank X and Tank Y into Tank Z is the same.

Total number of guppies transferred from Tank X and Tank Y into Tank Z
= 0.6 u + 0.4 u
= 1 u

3 u = 60

1 u = 60 ÷ 3 = 20

Number of more guppies in Tank Z than Tank Y
= 3 u - 0.6 u
= 2.4 u
= 2.4 x 20
= 48

Answer(s): 48