Question

Isaac has a total of 90 pennies, nickels, and quarters. He has 3 1/2 times as many quarters as nickels and 1/2 as many pennies as nickels. How many of each coin does he have?

Answer 1

see below

Explanation:

90 x, y, z

x pennies =1/2y

y nickels

z quarters = 3 1/2 y

so 1/2y+y+3 1/2 y =90

total 5y =90

y =18

x=9

z = 63