What is the weight of the body on the surface of the moon, if on planet a it weighs 96n where
ga=4.8m/s^2

A body's weight is equal to its mass times the acceleration due to gravity. So the body's weitght on planet A is:


W_a = m g_a


From the data you've been given you can calculate the body's mass. To find it's weight on the moon you then multiply that mass by the moon's value for acceleration due to gravity - call it g_{moon}- I suspect that they give you that value in your text.

Weight on planet A = 96N
Gavitational Acc Ga=4.8 m per sq sec
Mass = 96/4.8 = 20 kg

Now,
Gavitational Acc on Moon=1.63 m per sq sec
Weight on Moon = 20*1.63 = 32.6 N