Question 971974
n, d, q, the count of five cent, ten cent, and twenty-five cent coins.


{{{system(0.05n+0.1d+0.25q=5.35,d=1+2*n)}}}


{{{system(n+2d+5q=107,d=2n+1)}}}


{{{n+4n+2+5q=107}}}


{{{5n+5q=105}}}


{{{n+q=21}}}


You could try a revised system of
{{{system(n+q=21,d=2n+1)}}} and look for any combinations that will work.  You need natural numbers only.  Try starting with q=1, solve for n, and see what this gives you for the d equation; and then work upwards for q.  Maybe you could have more than one solution.