tax is $2.40 ...? The amount of sales tax varies directly with the cost of the purchase. If the sales tax is $2.40 on a purchase of $40.00, what would be the sales tax on a purchase of $60.50?
A) $3.03
B) $3.63
C) $4.80
D) $4.24
and
The cost of sending a letter is directly proportional to...
