The quantity of heat needed to melt ice = mL (where m is the mass of ice and L is the specific latent heat of fusion of ice)
Q = 50×336=16800J but this is 70% of the total heat supplied so that we have,
70% total heat = 16800J
70100 of total heat = 16800J
⇒ Total heat supplied = 16800×10070=24000J
