question_answer

One litre of water at\[~\mathbf{20}{}^\circ \mathbf{C}\] is mixed with one litre of water at\[\mathbf{30}{}^\circ \mathbf{C}\]. The temperature of the mixture will be:

A) \[50{}^\circ C\]    

B) less than \[20{}^\circ C\]

C) between \[20{}^\circ C\]and\[~30{}^\circ C\]         

D) \[10{}^\circ C\]

E) None of these