Maria bought 56 stamps at the post office in 37¢ and 20¢
denominations. If she paid $18 for the stamps, how many of each denomination
did she buy?
2007-08-08 06:13:32 · 5 answers · asked by Anonymous in Science & Mathematics ➔ Mathematics
If she bought x stamps of 37 cents and y stamps of 20 cents,
37x + 20y = 1800 (1 dollar is 100 cents)
x + y = 56
20x + 20y = 1120
Subtracting that from the first equation,
17x = 1800 - 1120 = 680
x = 680/17 = 40
So, Maria bought 40 stamps of 37 cents and 16 stamps of 20 cents. You can check that the answer is correct by substituting these values in the first equation.
2007-08-08 06:25:10 · answer #1 · answered by Swamy 7 · 1⤊ 0⤋
x + y = 56
.37x + .20y = 18
Solving these, the answer is 40 of the 37 cent stamps and 16 of the 20 cent stamps.
2007-08-08 13:27:03 · answer #2 · answered by Z-Dub 2 · 0⤊ 0⤋
x+y=56
y=56-x
37x + 20y = 1800
37x + 20(56-x) =1800
37x + 1120 - 20x = 1800
17x = 680
x = 40
40 @37cents, 16 @20 cents
2007-08-08 13:26:02 · answer #3 · answered by Baccheus 7 · 0⤊ 0⤋
20 x .37= 7.40 53x.20=10.60 + 7.40= 18.00 so I would have to buy 73 stamps GOD I'M AN IDIOT
2007-08-08 13:30:33 · answer #4 · answered by chillindaver 2 · 0⤊ 0⤋
40 $0.37 stamps
16 $0.20 stamps
2007-08-08 13:26:03 · answer #5 · answered by csmithballsout 4 · 0⤊ 0⤋