Question 1026952
q, d, n, quarters dimes nickels;


{{{system(0.25q+0.1d+0.05n=1.00,q+d+n=12)}}}


{{{5q+2d+n=20}}}


You have really just two equations but three unknown variables.  The most restrictive variable would be q for quarters.  You know the quantity could only be from 1 to 3, so just try those different values and solve for d and n.