Leaky bucket

Problem:

Solution:

Bucket A is leaking at a rate $\frac{\frac{7}{4}}{\frac{3}{2}} = \frac{7}{6} = \frac{21}{18}$
Bucket B is leaking at a rate $\frac{\frac{5}{6}}{\frac{3}{4}} = \frac{10}{9} = \frac{20}{18}$

Therefore bucket B is leaking slower.