SOLUTION: pat bought 45 stamps , some for 10c and some for 18c. If he spent $6.66 altogether, how many 10c stamps did he buy?

Question 935846: pat bought 45 stamps , some for 10c and some for 18c. If he spent $6.66 altogether, how many 10c stamps did he buy?
Found 2 solutions by TimothyLamb, josmiceli:
Answer by TimothyLamb(4379) (Show Source): You can put this solution on YOUR website!
x = number of 10 cent stamps
y = number of 18 cent stamps
---
x + y = 45
10x + 18y = 666
---
put the system of linear equations into standard form
---
x + y = 45
10x + 18y = 666
---
copy and paste the above standard form linear equations in to this solver:
https://sooeet.com/math/system-of-linear-equations-solver.php
---
solution:
x = number of 10 cent stamps = 18
y = number of 18 cent stamps = 27
---
Free algebra tutoring live chat:
https://sooeet.com/chat.php?gn=algebra
---
Solve and graph linear equations:
https://sooeet.com/math/linear-equation-solver.php
---
Solve quadratic equations with quadratic formula:
https://sooeet.com/math/quadratic-formula-solver.php
---
Solve systems of linear equations up to 6-equations 6-variables:
https://sooeet.com/math/system-of-linear-equations-solver.php
---
Answer by josmiceli(19441) (Show Source): You can put this solution on YOUR website!
Let = number of 10 cent stamps
Let = number of 18 cent stamps
-----------------------------------
(1)
(2) ( in cents )
----------------------------------
(2)
Multiply both sides of (1) by and
subtract (1) from (2)
(2)
(1)
-----------------------

and
(1)
(1)
(1)
He bought 18 10c stamps

RELATED QUESTIONS
Aquilla buys 50 stamps, some for 10c and some for 20c. If she spend 6,40 altogether, how... (answered by CubeyThePenguin)
John bought 75 stamps for 19.94. Some were 20 cent stamps and some were 33 cent stamps.... (answered by edjones)
Suppose you bought some 32c stamps and some 20c stamps. You spent $3.92 for 16 stamps.... (answered by solver91311)
suppose you bought some .32 cent stamps and some .20 cent stamps. You spent $3.92 for... (answered by rwm)
James bought 80 postage stamps for which he paid $3.50. Some were 3-cents stamps and some (answered by checkley77)
Joe Lick bought some 20-cent and 25-cent stamps. He bought 32 stamps in all, and paid... (answered by drj)
Allan bought some 5 cent stamps and some 20 cent stamps. The entire purchase was $7 he... (answered by oberobic)
Chang bought some 25 cent stamps and some 15 cent stamps and paid $5.00. How many 25 cent (answered by Edwin McCravy)
Mr. Lowe bought some three cent stamps and some two cent stamps. The total cost was... (answered by checkley77)