Answer: There are 79 toys they can build.
Explanation:
Since we have given that
Number of candy canes Candy eats be 'c'.
Number of candy canes Melvin eats be 'm'.
So, the number of toys they build is given by

Number of candy canes eat by Calvin = 5
Number of candy canes eaten by Melvin = 3
So, the total number of toys they build is given by

Hence, there are 79 toys they can build.