Answer
17 pennies, 20 nickels, 16 dimes
Work Step by Step
2.77 in change, all pennies, nickels, and dimes
53 coins, 4 more nickels than dimes
Let the number of pennies, nickels, and dimes be represented by $p$, $n$, and $d$, respectively
$p+n+d=53$
$n=4+d$
$.01*p+.05*n+.1d=2.77$
$n=4+d$
$n-d=4+d-d$
$n-d=4$
$p+n+d=53$
$n-d=4$
$.01*p+.05*n+.1d=2.77$
Please see the applicable matrices.