Question

Sonji has $5.25 in nickels and dimes.The coin value can be modeled by the equation 0.10 d plus 0.05 n equals 5.25, where d represents the number of dimes and n represents the number of nickels. If Sonji has 21 dimes, how many nickels does she have?

35
42
63
105

Answer 1

simple answer is C

Explanation:

doing the exam now<3.

Answer 2

Sonji has 63 nickels.

Explanation:

Here we just have to take the given expression, and replace the amount of dime Sonji has.

So, we know that the situation is modeled by:

`0.10d+.0.05n=5.25`

Where
`d` and
`n` are dimes and nickels respectively. The model make totally sense, because each dime values 10 cents or $0.10, and each nickel values 5 cents or $0.05.

So, if Sonji has 21 dimes, we replace this in the model and solve for
`n`:

`0.10d+.0.05n=5.25\\0.10(21)+0.05n=5.25\\2.1+0.05n=5.25\\0.05n=5.25-2.1\\n=(3.15)/(0.05)\\ n=63 \ nickels`

Therefore, according with this result, Sonji has 63 nickels.