How much will it cost him to send 3 small packages and 7 large packages?

Question

David is mailing packages. Each small package costs him $2.90 to send. Each large package costs him $4.20 . How much will it cost him to send 3 small packages and 7  large packages?

 

 

Answer 1

3S + 7 L = 3(2.9) + 7(4.2) = 8.7+29.4 = 38.1 = $38.10 to send 3 small and 7 large packages

As sort of a check, to make sure you're in the right price range

round off the costs to $3 and $4, then 3x3 = $9 and 7x$4 = 28, 9+28 = 37. That's within about $1 of your calculation. That gives some confidence you have the right answer