Let q and n represent the number of quarters and nickels respectively.
q=3n and .05n+.25q=1.6 These are the conditions in mathematical terms.
To solve, use the value of q from the first equation in the second equation to get:
.05n+.25(3n)=1.6 carry out indicated multiplication on left side
.05n+.75n=1.6 combine like terms on left side
.8n=1.6 divide both sides by .8
n=2, since q=3n
q=6
So Peggy had 2 nickels and 6 quarters.
