Ivan bought 35 stamps. some of these stamps cost $0.15 each, and the rest cost $0.40 each. if the total value of the stamps he bought is $7.25, determine the number of $0.15 stamps that ivan bought.

  27

Step-by-step explanation:

Let x represent the number of $0.15 stamps Ivan bought. Then the value of his stamps is ...

  0.15x +0.40(35-x) = 7.25

  -0.25x +14.00 = 7.25 . . . . . eliminate parentheses, collect terms

  -0.25x = -6.75 . . . . . . . . . . . subtract 14.00

  x = 27 . . . . . . . . . . . . . . . . . . divide by -0.25

Ivan bought 27 $0.15 stamps.

answer: the answer is e

step-by-step explanation: