PHysics questions?

how many joules of heat energy do you need to heat 200 ml of water from 20C to 80C. Show calculations...4.19J/gC for specific heat of water..... 2nd part how many times as much heat energy as it took in the previous part would it take to heat 100ml of water from 60 to 90C? 3rd part how long would it take if the water in the previous question were being heated continuously by a 50 watt heater