Sue has 100 dimes and quarters. If the total value of the coins is $21.40, how many of each kind of coin does she have?

1 answer:

8 0

Let's set up the equations we know.
Q+D=100, where Q=number of quarters, and D=number of dimes
.25Q + .1D = 21.40 (because a quarter is worth .25 and a dime worth .10)

Using the first equation, let's isolate one of our variables. I'll pick Q.
Q+D=100
Subtract D from each side
Q=100 - D

Now that we have this new equation, let's plug it into our second equation.
.25Q + .1D = 21.40
.25(100-D) + .1D = 21.40
Distribute the .25
25 - .25D + .1 D = 21.40
Combine like terms
25 - .15D = 21.40
Subtract 21.40 from each side
3.6 - .15D = 0
Add .15 D to each side
3.6 = .15D
Divide each side by .15
D = 24

Now that we have D, we can solve for Q
Q= 100 - D
= 100 - 24
Q = 76

Sue has 24 dimes and 76 quarters.

Let's check our work to make sure.
.25(76) + .1(24) =
19 + 2.4 = 21.4 √

You might be interested in

Carolyn is building a pen for a dog. The PERIMETER of the pen is 52 ft. The material is sold by the yard. It is 10.99 dollars pe

Mazyrski [523]

We know that the fence is 52 feet long, but since it's sold in yards, we need to somehow convert feet to yards.
First, we need to find a little something called a conversion factor. Basically, we need to see what we can do to get from one foot to one yard.
Well, how many feet are there in a yard? 3. So now we know that one foot is 1/3 of a yard.

So to convert 52ft to yards, we need to divide by 3. What's 52 divided by 3?
17.33.
Now we just need to multiply that by 10.99 so that we can find out the cost.
We get 190.45. That's your answer!

It all cost $190.45

Don't forget to rate this answer the Brainliest!

8 0

3 years ago

I will mark as brainest

daser333 [38]

subtract 3 from 23 and u will get 20 then divide 2 by 2 and 2 by 20

x= 10

8 0

3 years ago

Read 2 more answers

The hypotenuse of a right triangle is 3cm and one of the legs is 1cm. What is the length of the other leg?

Zolol [24]

Check the picture below.