Question

Andres has $1.50 in dimes and nickels. If he has 9 more nickels than dimes, how many of each coin does he have?He has ? nickels and ? dimes.

Answer 1

Let's use the variable x to represent the number of dimes and y to represent the number of nickels.

If the total value is $1.50, we can write the equation:

$0.1x+0.05y=1.5$

Also, if there are 9 more nickels than dimes, we have our second equation:

$y=x+9$

Using this value of y from the second equation into the first one, we have:

$\begin{gathered} 0.1x+0.05(x+9)=1.5 \\ 0.1x+0.05x+0.45=1.5 \\ 0.15x=1.5-0.45 \\ 0.15x=1.05 \\ x=\frac{1.05}{0.15} \\ x=7 \\ \\ y=x+9 \\ y=7+9 \\ y=16 \end{gathered}$

Therefore Andres ha 16 nickels and 7 dimes.