Question 703238
let  quarters will be {{{3x}}} and nickels will be ${{{x}}}

if Mark had {{{3}}} times as many quarters as nickels, and if he had ${{{1.60}}} in all, than {{{0.25*3x+0.05x=1.6}}}:

{{{0.75x+0.05x=1.6}}}

{{{0.80x=1.6}}}

{{{x=1.6/0.80}}}

{{{x=2}}}.....nickels 

and {{{3*2=6}}} quarters