Let n be the number of nickels and d be number of dimes.
The number of dimes is 3 more than twice the number of nickels. This can be written as,
[tex]d=3+2n[/tex]The value of one nickel is 5 cents, and value of one dime is 10 cents. Also, 1 dollar is 100 cents.
Therefore,
[tex]\begin{gathered} 5n+10d=1.80 \\ 5n+10(3+2n)=180 \\ 25n=180-30 \\ n=6 \end{gathered}[/tex]Thus, the number of nickels is 6
