Question 829076
Let {{{N}}},{{{D}}},{{{Q}}} be the number of each coin he has. 
1.{{{D=2*N}}}
2.{{{Q=D-2}}}
3.{{{0.05*N+0.10*D+0.25*Q=3.25}}}
Substitute 1 and 2 into 3,
{{{0.05*N+0.10*2*N+0.25*(D-2)=3.25}}}
{{{0.05*N+0.2*N+0.25*(2*N-2)=3.25}}}
Multiply both sides by 100,
{{{5N+20N+25(2N-2)=325}}}
{{{5N+20N+50N-50=325}}}
{{{75N=375}}}
{{{N=5}}}
Then from eq. 1,
{{{D=2*5}}}
{{{D=10}}}
Then from eq. 2,
{{{Q=D-2}}}
{{{Q=8}}}
He has 5 nickels, 10 dimes, and 8 quarters.