Answer :
This might be right. Im not quite sure. This is what my 5th grade science teacher told me. 'Look at the 2 LR's and add them together. Then look at the total amount which is 32. When you add the 2 LR's you get 17. So subtract 17 from 32 and you get 15. So: C:15 is your answer." (LR's stands for liquid reactants)
10+17=17
Total amount is 32
32-17=15
15 is you mass
Hope this Helps