Tank W contained 4 times as many guppies as Tank X. When 40% of the guppies in Tank W and 20% of the guppies in Tank X were transferred to Tank Y, Tank Y had 270 guppies, which was 25% more guppies than before. How many less guppies were there in Tank X than Tank W in the end?

	Tank W	Tank X	Tank Y
Before	4 u	1 u	4x1.8 = 7.2 u
Change	- 1.6 u	- 0.2 u	+ 1x1.8 = + 1.8 u
After	2.4 u	0.8 u	5x1.8 = 9 u

Number of guppies that were transferred from Tank W to Tank Y
= 40% x 4 u
= ⁴⁰₁₀₀ x 4 u
= 1.6 u

Number of guppies that were transferred from Tank X to Tank Y
= 20% x 1 u
= ²⁰₁₀₀ x 1 u
= 0.2 u

25% = ²⁵₁₀₀ = ¹₄

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

Total number of guppies transferred from Tank W and Tank X into Tank Y
= 1.6 u + 0.2 u
= 1.8 u

9 u = 270

1 u = 270 ÷ 9 = 30

Number of less guppies in Tank X than Tank W
= 2.4 u - 0.8 u
= 1.6 u
= 1.6 x 30
= 48

Answer(s): 48