A body of weight 10kg is partly immersed in water. If the weight of the body in the water is 7.5kg , what volume of water is displaced ( take density of water=1.2 units

Answer 1

10 - 7.5 = 2.5 kg of water displaced
2.5 kg * 1.2 units /kg

I can not guess what your units might be.
water is normally about 1000 kg/m^3 or 1 gram/ cm^3

if you are using 1.2 grams/cm^3
then
you have 2,500 grams
2500 grams * 1.2 cm^3/gram = 3,000 cm^3