Given data:
The total numbers of nickel and dimes are n+d=19.
The expression for the total cost is 0.05n+0.1d=1.3.
The first equation can be written as,
![n=19-d](https://img.qammunity.org/2023/formulas/mathematics/college/cv79m6subng2b6ka0esjs3pwq5ygtgrxa3.png)
Substitute above exprression in second equation.
![\begin{gathered} \text{0}.05(19-d)+0.1d=1.3 \\ 0.95-0.05d+0.1d=1.3 \\ \text{0}.05d=0.35 \\ d=7 \end{gathered}](https://img.qammunity.org/2023/formulas/mathematics/college/da90mqumyuosr3fyvyna3j72z458gxmdd5.png)
The numbers of nickels are,
![\begin{gathered} n=19-7 \\ =12 \end{gathered}](https://img.qammunity.org/2023/formulas/mathematics/college/3ojye7b6q1qm80dcqck13a8yy6k1vr17g5.png)
Thus, the numbers of nickels are 12, and numbers of dimes are 7.