Each small package costs him $2.80
3 small packages will cost him 3 x $2.80 = $8.4
Each large package costs him $3.60
7 large packages will cost 7 x $3.60 = $25.2
Cost to send 3 small packages and 7 large packages = $8.4 + $25.2
= $33.6
The answer is $33.6