Postcard stamps are 20 cents each, while letter stamps are 33 cents each. If you have 50 stamps worth $12.60, how many of each type do you have?
I don't even know where to begin with this Q.
let the number of 20 cent stamps be x
then the number of 33 cent stamps is 50-x
solve:
20x + 33(50-x) = 1260
After solving the equation i get 3.9=x
??? isnt there a way you can solve it by letting x= number of postcard stamps and then y= number of letter stamps?
sure:
number of postcards stamps x
number of letter stamps y
x + y = 50
20x + 33y = 1260
from the first:: y = 50-x
then in the second
20x + 33(50-x) = 1260
well, look at that! I had that in the first line.
solution:
20x + 1650 - 33x = 1260
-13x = -390
x = 30
then y = 50-x = 50-30 = 20
(how did you get a decimal??? of 3.9x ? )
THANK YOU!!!!!! sorry! i feel like a waste of time for you, but im just not that smart ;)
number of postcards stamps x
number of letter stamps y
x + y = 50
20x + 33y = 1
20x + 1650 - 33x = 1260
-13x = -390
x = 30
then y = 50-x = 50-30 = 20
How do you set this as a matrix equation?
To solve this problem, we need to set up a system of equations based on the given information.
Let's assume the number of postcard stamps is represented by the variable 'P' and the number of letter stamps by 'L'.
According to the problem, the cost of each postcard stamp is 20 cents and the cost of each letter stamp is 33 cents. We also know that the total number of stamps is 50 and their total worth is $12.60.
Now we can set up the equations:
1. The total number of stamps: P + L = 50
2. The total worth of the stamps: 20P + 33L = 1260 cents (as $12.60 is equal to 1260 cents)
We have a system of two equations with two variables. To solve this system, we can use either substitution or elimination method.
Let's use the elimination method:
Multiply equation 1 by 20: 20P + 20L = 1000
Now subtract this equation from equation 2:
(20P + 33L) - (20P + 20L) = 1260 - 1000
This simplifies to:
13L = 260
Divide both sides by 13:
L = 20
Now substitute the value of L into equation 1:
P + 20 = 50
Subtract 20 from both sides:
P = 30
So, you have 30 postcard stamps and 20 letter stamps.