The picture below shows two cases in which a person is trying to burn the paper cup. In case 1, the cup has water in it and in case 2, it is empty and dry. Identify in which of the cases the paper will burn.
In case 2, the empty paper cup reaches its ignition temperature and catches fire. In case 1, the heat supplied to the paper cup is transferred to water in it. So, in the presence of water, the ignition temperature of the paper is not reached. So, the paper would not burn in case 1.