Question

You buy 80 stamps for 17 dollars some stamps were 15 cents each and the others were 25 cents each. how many of each kind did you buy

Answer 1

answer: ten 15¢ stamps and forty 20¢ stamps.

Explanation:

because i just took the quiz

Answer 2

30 of the 15 cent stamps and 50 of the 25 cent stamps

Explanation:

Create a system of equations, where x is the number of 15 cent stamps and y is the number of 25 cent stamps:

x + y = 80

0.15x + 0.25y = 17

Solve by substitution by rearranging the first equation:

x + y = 80

x = 80 - y

Substitute 80 - y as x into the second equation:

0.15x + 0.25y = 17

0.15(80 - y) + 0.25y = 17

12 - 0.15y + 0.25y = 17

12 + 0.1y = 17

Solve for y:

0.1y = 5

y = 50

Plug in 50 as y into the first equation, and solve for x:

x + y = 80

x + 50 = 80

x = 30

So, you bought 30 of the 15 cent stamps and 50 of the 25 cent stamps