math question?

Question

can you help me answer this math problem and give me the steps for it to thx
-the value of 92 stamps is $14. if there are only 10-c and 25-c stamps, how many 10-c stamps are there

Answer 1

First, set up equations for what you know:

x is number of .10 stamps
y is number of .25 stamps

x(.10) + y(.25) = 14.00

Also, you know that there are 92 stamps, so:

x + y = 92

Now, you can solve this equation for one term in relation to the other, like this:

x = 92 - y

substitute this into the first eqation and solve it:

x(.10) + y(.25) = 14.00

(92 - y)(.10) + 0.25y = 14

9.2 - 0.10y + 0.25y = 14

-0.10y + 0.25y = 4.8

0.15y = 4.8

y = 32 quarters
----------------------
Since there are 92 coins:

x + y = 92

x + 32 = 92

x = 60

Now, check your work:

60(0.10) + 32 (0.25) = 14.00
6.00 + 8.00 = 14.00
14.00 = 14.00

Done!

Answer 2

You can pick a variable to stand for the number of 10 cent stamps, say x. Then since there are 92 total stamps, the number of 25 cent stamps is 92 - x.

Now multiply the number of each kind of stamp by its value and add to get the total value:

10x + 25(92 - x) = 1400 in cents

Now do it out (distribute the 25)

10x + 2300 - 25x = 1400

You can probably figure what to do from here but if you can't send an IM or look below for a more complete answer

Answer 3

Let x= the number of 25c stamps
Let 92-x= the number of 10c stamps
Together in pennies they = 1400 cents

25x +10(92-x)=1400
25x +920 - 10x=1400
15x=480
x=32 There are 32 25c stamps, and 92-32 or 60 10c stamps

Answer 4

# of 10c stamps: x
# of 25c stamps: y

We'll set up two equations, then solve them. The total number of stamps is 92, so

x+y=92

Each x stamp is 10c, and each y stamp is 25c. The total value is $14, or 1400c. Let's set up an equation showing this.

10x+25y=1400

Divide through by 5, so

2x+5y=280

Let's break this down to

(x+y)+(x+y)+3y=280

We can now substitute 92 for any x+y

92+92+3y=280
3y=96
y=32

x=92-32=60

Instead of substituting for x+y, you could have substituted for one variable (x=92-y or y=92-x) and the answer would be the same. I find my way easier to sort of fun to think about, but if you've been taught another way your teacher might want you to stick with that. Whatever works for you.


10c stamps: 60

At this point, I checked mentally but didn't write it down. It's fairly easy to do.

Hope this helps.

Answer 5

let x be the number of 25 cent stamps
then 92 - x is the number of 10 cent stamps

0.25x + 0.10 (92-x) = 14
0.25x - 0.10x = 4.8
0.15x = 4.8
x = 32

there are 32 stamps that cost 25 cents and 60 stamps that cost 10 cents

hope this helps!

Answer 6

x + y = 92
x = 92 -y

10x + 25y = 1400
10(92 - y) + 25 y = 1400
920 - 10 y + 25 y = 1400
15y = 480
y = 32
x = 92 - 32 = 60

Check:
10*60 + 25*32 = 600 + 800 = 1400

Answer 7

Will this work?

Using Hayharbr's idea, can we say the total value of the stamps is

.1x + .25(92 - x) = 14

Forget solving this. Let's look at Hottychic's answer instead. She buys FIVE stamps whose total value is 95 cents!!! Isn't this supposed to be 92 stamps whose total value is $14?!! Hey, Hottychic, forget about math and stick to questions about makeup.

Answer 8

60 10 cent stamps.
32 25 cent stamps.
Plain and simple.

Answer 9

you divide 95 by 25 and you get 3 with leaves 20 left so that would make 3-25cent stamps and 2- 10 cent stamps..