Answer:
$27.50
Step-by-step explanation:
To find the total value of all her 50-cent coins, we first need to find the amount of 50-cent coins Jenny have. This can be done through the formation of, and subsequently solving, two simultaneous equations.
Start by defining the variables used.
Let the number of 20-cent coins be x and the number of 50-cent coins be y.
x= y +60 -----(1)
Value of 50-cent coins= $y(0.50)
Value of 20-cent coins= $x(0.20)
0.5y= 0.2x +4.50 -----(2)
Let's solve by substitution.
Substitute (1) into (2):
0.5y= 0.2(y +60) +4.5
Expand:
0.5y= 0.2y +12 +4.5
0.5y= 0.2y +16.5
0.5y -0.2y= 16.5
0.3y= 16.5
Divide both sides by 0.3 to find y:
y= 16.5 ÷0.3
y= 55
Since there are 55 50-cent coins, the value of all her 50-cent coins is:
$y(0.50)
= $[55(0.50)]
= $27.5
Additional:
To learn more about solving equations, do check out the following!
