Question 238050
Hello!  First let's find out how many coins of each Penny has before we calculate their value.  We know Penny has a total of 24 coins, 3 times as many dimes as quarters, so we can say this:
x = quarters
3x = dimes
24 = total coins ...your equation is now:
{{{x+3x=24}}}
Solve for x to find the number of quarters Penny has.
{{{4x=24}}}
{{{x=(24/4)}}}
{{{x=6}}}
Penny has 6 quarters.  Now, figure out how many dimes Penny has.
Since 3x = dimes
{{{(3*6)=18}}}
Penny has 18 dimes.
Now mulitply the number of quarters by its monetary value (0.25) and multiply the number of dimes by its monetary value (0.10).
.
{{{(6*0.25)=1.50}}} ...same as $1.50
{{{(18*0.10)=1.80}}} ...same as $1.80
.
Now add them together to find the correct answer to the problem.
I'll let you finish it.  :)