Why 373-303 ?

I dont quite understand your working

373 = 273 +100C in Kelvin

I can explain, if it will help. Consider the total heat removed is from the water in the bottle + the heat from the copper bottle.

This is equal to ( water reducing from 100 deg c to 30 deg c) 176400J + ( copper bottle reducing from 100 deg c to 30 deg c ) 2709 J = 179109J.

The amount of ice is added at 0 deg c. So first it will try to gain the latent heat, and all the ice will become water at 0 deg c. Then this water will gain more heat to become water at 30 deg c.

So for ice becoming water, it is mass times latent heat. Then for ice to gain more heat is mass x specific heat x temperature change. You will have to sum these heats together in order, since this is the total heat removal from the bottle. Then equate this to the previously calculated 179109J and solve for m. That is what I have done.

Did you understand now ?

Not really still... i think ur explanation abit too confusing for me. Ur effort is still appreciated thanks