Question

mayra has $2.95 in nickels and dimes. the number of dimes is 3 less than twice the number of nickels. find the number of nickels.

Answer 1

Mayra has 13 nickels

Explanation:

Given

Represent dimes with D and nickels with N.

So, from the first statement:

`0.10D + 0.05N = 2.95`

From the second statement:

`D = 2N - 3`

Required

Find N

Substitute 2N - 3 for D in
`0.10D + 0.05N = 2.95`

`0.10(2N - 3) + 0.05N = 2.95`

Open bracket

`0.10*2N - 0.10*3 + 0.05N = 2.95`

`0.20N - 0.30 + 0.05N = 2.95`

Collect Like Terms

`0.20N + 0.05N = 2.95+0.30`

`0.25N = 3.25`

Make N the subject:

`N = (3.25)/(0.25)`

`N = 13`