Solution:

Concept: Free fall under gravity.
Formula: Distance \(h = \frac{1}{2}gt^2\) ⇒ time \(t = \sqrt{\frac{2h}{g}}\), so \(t \propto \sqrt{h}\)
For body A, \(h_A = 16\text{ m}\); for body B, \(h_B = 25\text{ m}\).
Ratio: \(t_A/t_B = \sqrt{h_A/h_B} = \sqrt{16/25} = 4/5\).