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Question

A shipping company delivered 160 packages one day. The cost of regular delivery is $6.50, and the cost for express delivery is $17.50. Total shipping revenue for the day was $1513. How many of each kind of delivery were made?

Answer 1

1513=6.5*x+17.5*(160-x)

1513=6.5x+2800-17.5x

1513-2800=6.5x-17.5x

-1287=-11x

1287=11x

x=1287/11

x=117 regular deliveries

160-117=43 express deliveries