Answer:
21 shells
Step-by-step explanation:
10+23+21=64
64/3=21.33
always round down, you'll have one left over
18
10+23+21= 54
54/3=18
18r-4
Here is your anwer
81
55- 3m is the awnser for this question
using the phytogaran theory we get 17 inch as the length of the diagonal
