Algebra
posted by Word Problem .
Can someone please help with this?
Allen bought 20 stamps at the post office in 37¢ and 20¢ denominations. If the total cost of the stamps was $7.06, how many 37¢ stamps did Allen buy?
A) 15
B) 16
C) 17
D) 18

Set up a system of equations to model this situation. (Note that a system of equations is TWO different equations.)
Let x be the number of 37cent stamps, and let y be the number of 20cent stamps.
What two equations did you get? 
x+y=7.06

That's only one equation.
Anyway, the number of stamps that he buys is 20.
The other equation will deal with the stamp prices.
What do you get? 
37x+20y=7.06

That's close. The stamps are in CENTS, though.
.37x + .20y = 7.06
That is one equation. The other equation deals with how many stamps he bought. What is it? 
x+y=20
and
37x + .20y = 7.06 
Good. Our two equations are:
.37x + .20y = 7.06
x + y = 20
We're trying to find the number of 37cent stamps (x). We can solve this system of equations by substitution. Solve the second equation for y, and then plug that into the first equation.
We now only have x's in the equation, so solve it as you would any other equation. 
Would the answer be D  18 .37 stamps?

Yup. Nice job.
Respond to this Question
Similar Questions

math,algebra
Can someone help me put this into equations where i can solve them thanks. Problem #1 Allen bought 20 stamps at the post office in 37cents and 20cents denominations. If the total cost of the stamps was $7.06, how many 37cents stamps … 
algebra
Allen bought 20 stamps at the post office in 37 cents and 20 cents. the total cost of the stamp was $7.06. How many 37cents stamp did Allen Buy 
math
in a series of stamps annie must buy six of each one cost $4.00 one cost $2.50 one cost $1.20 one cost $1.00 she had to post a parcel and totals cost of postage was $25.70.what stamps can she use from the selection to make up this … 
Math (Please Help)
A man went to a post office to buy stamps. He bought x, 50 cent stamps and y, 25 cent stamps for $3.50. If he bought twice as many 50 cent stamps and half as many 25 cent stamps, the cost would be $4.75. Evaluate x and y 
Algebra
a colection of stamps consist of 2 cent stamps, 8 cent stamps, and 14 cent stamps. The number of 2 cent stamps is five more then twice the number of 8 cent stamps.the number of 14 cent stamps is three times the number of 8 cent stamps. … 
algebra
An executive bought 300 stamps for $73.80. The purchase included 15 cent stamps, 20 cent stamps, and 40 cent stamps. The number of 20 cent stamps is four times the number of 15 cent stamps. How many 40 cent stamps were purchased? 
Algebra
A stamp collection consists of 3¢, 12¢, and 15¢ stamps. The number of 3¢ stamps is three times the number of 12¢ stamps. The number of 15¢ stamps is three less than the number of 12¢ stamps. The total value of the stamps in … 
Math please help
Carol has a collection of 100 stamps the graph below shows the percentage of stamps she has from each country how many more of Carols stamps are from France than from Norway? 
pre algebra
Julie went to the post office and bought both $0.49 stamps and $0.34 postcards for her office's bills. She spent $62.60. The number of stamps was 20 more than twice the number of postcards. How many of each did she buy? 
Math
Mr. Dinkelspiel bought $32.56 worth of stamps. He bought 20 more 19cent stamps than 50cent stamps. He bought twice as many 32cent stamps as 19 cent stamps. How many of each kind did he buy?