Question 163329
Write an equation for each statement/phrase
:
"Zack has $1.30 in pennies, nickels, and quarters."
.01p + .05n + .25q = 1.30
:
"He has twice as many nickels as pennies"
n = 2p
or
p = .5n; (we are going to try and solve for n, first. Get everything in terms of n)
:
"and 7 less quarters than nickels."
q = n-7
:
 How many of each coin does Zack have?
:
.01p + .05n + .25q = 1.30
In this equation, substitute .5n for p and (n-7) for q
;
.01(.5n) + .05n + .25(n-7) = 1.30
.005n + .05n + .25n - 1.75 = 1.30
.305n = 1.30 + 1.75
.305n = 3.05
n = {{{3.05/.305}}}
n = 10 nickels
;
Now, using the equations we have, you should be able to find p and q
Then check the solution in the original Total$ equation