Problema Solution
A coin purse contains coins with a value of $1.60. The purse contains nickels and quarters. There are three times as many nickels as quarters. Find the number of nickels in the purse.
Answer provided by our tutors
let
x = the number for nickles
y = the number of quarters
1 nickle = 5 cents
1 quarter = 25 cents
1$ = 100 cents
$1.60 = 160 cents
the value of all the nickles + the value of all the quarters = the total value of the purse ($1.60)
5*x + 25*y = 160
there are three times as many nickels as quarters
3*x = y
by solving the system of equations
3*x = y
5*x + 25*y = 160
if we substitute for y = 3x in the second equations we find
80*x = 160
x = 2 nickles
There are 2 nickles in the purse.