Problema Solution
Alyssa has $7.70. If she had 10 pennies, twice as many dimes as quarters, and 1/2 as many nickels as quarters, how many quarters did she have?
Answer provided by our tutors
1 penny = 1 cent
1 nickle = 5 cents
1 dime = 10 cents
1 quarter = 25 cents
let
x = the number of nickles
y = the number of dimes
z = the number of quarters
z = 2*y
x/2 = z
10 + 5*x + 10*y + 25*z = 770
by solving the system of 3 equations
y = z/2
x = 2*z
5*x + 10*y + 25*z = 760
we find
x = 38 nickles
y = 9.5 dimes
z = 19 quarters
Alyssa had 19 quarters.