SOLUTION: andy has eighteen coins made up of quarters and half dollars, and their total value is $7.50. How many quarters does he have?

Question 600419: andy has eighteen coins made up of quarters and half dollars, and their total value is $7.50. How many quarters does he have?
Answer by alicealc(293) (Show Source): You can put this solution on YOUR website!
number of quarters coins = q
number of half-dollars coins = h

q + h = 18

1/4 q + 1/2 h = 7.5
multiply all by 4:
q + 2h = 30

use the elimination procedure:
q + h = 18
q + 2h = 30
------------ (-)
-h = -12
h = 12

q + 12 = 18
q = 18 - 12 = 6

So he has 6 quarters

RELATED QUESTIONS
Solve the problem. Andy has 8 coins made up of quarters and half dollars, and their total (answered by checkley77)

Andy has 21 coins made up of quarters and half dollars, and their total value is $6.50.... (answered by josmiceli)

Andy has 8 coins made up of quarters and half dollars, and their total value is $2.50.... (answered by stanbon)

andy has 17 coins made up of quarters and half dollars, and their total value is $7.25.... (answered by algebrahouse.com)

Andy has 17 coins made up of quarters and half dollars, and their total value is $5.50.... (answered by Alan3354)

Andy has 17 coins made up of quarters and half dollars, and their total value is $4.75.... (answered by josgarithmetic)

Andy has 14 coins made up of quarters and half dollars their total value is$6.00 how many (answered by jim_thompson5910,algebrapro18)

Andy has 22 coins made up of quarters and half dollars, and their total value is 9.75.... (answered by richwmiller)

translate the problem into a pair linear equations in two variables.solve using... (answered by eggsarecool)