Question

Priam has pennies and dimes in a cup holder in his car. The total value of the coins is $4.21. The number of dimes is three less than four times the number of pennies. How many pennies and how many dimes are in the cup?

Answer 1

There are 11 pennies and 41 dimes in the cup.

Explanation:

Let the pennies be represented by = p

Let the dimes be represented by = d

The total value of the coins is $4.21. We get the first equation as:

`0.01p+0.10d=4.21` .......(1)

The number of dimes is three less than four times the number of pennies. We get the second equation as:

`d=4p-3` ......(2)

Substituting the value of d from (2) in (1)

`0.01p+0.10(4p-3)=4.21`

Solving this we get;

`0.01p+0.4p-0.3=4.21`

=>
`0.41p=4.21+0.3`

=>
`0.41p=4.51`

We get p = 11

And
`d=4(11)-3` =
`44-3`

We get d = 41

Therefore, there are 11 pennies and 41 dimes in the cup.