Heat capacity question.

I came across this question on an AQA past paper for which i do not have the mark scheme would anyone be so kind as to help me out? Cheers in advance.

'A cup contains 0.25Kg of water at at temperature of 15C. The water is heated by passing steam into it at 100C.

Specific heat capacity of water= 4200J Kg K. (per kilogram per kelvin)
specific latent heat of vapourisation of water= 2.3X10^6
Boiling point of water= 100C

Use the above data to calculate the minimum mass of water that is in the cup when the temperature of the water reaches its boiling point.'

Reply 1

teachercol

Heat gained by cool water to take it 100 = heat lost of steam as it condenses to water at 100.

0.25 x 4200 x 85 = m x 2 300 000

Work out the mass of steam - then add to to the mass of water to get mass in cup.