Continuous random variables — practice question

A bakery produces loaves of bread in batches. For one batch, the amounts of dried yeast and flour are $X$ kilograms and $Y$ kilograms, and $X$ and $Y$ have the independent distributions $\mathrm{N}(0.7, 0.02^2)$ and $\mathrm{N}(100.0, 3.0^2)$ respectively. Dried yeast is priced at $\$13.50$ per kilogram and flour at $\$0.90$ per kilogram. To make one batch of bread, the total of all other costs is $\$55$. The bakery sells each batch of bread for $\$200$.