A monkey of mass 20 kg is holding a vertical rope, which breaks under the weight of mass 25 kg. The maximum acceleration with which the monkey can climb up the rope is

2.5 m/$s^2$

weight of monkey (mg) = 20 g

Maximum weight that rope can carry (T) = 25 g

Let maximum acceleration with which the monkey can climb up the rope is a.

If T is maximum tension in the string then T - mg = ma

⇒25 g - 20 g = 20a

⇒ a = 2.5 m/$s^2$