Problema Solution
A student has a number of $60 and $120 savings bonds to use for part of her college expenses. The total value of the bond is $2100. There are 5 more $60 bonds than $120 bonds. How many of each type of bond does she have ?
Answer provided by our tutors
let
x = the number of $60 bonds
y = the number of $120 bonds
the value of the $60 bonds + the value of the $120 bonds = the total value ($2100)
60*x + 120*y = 2100
there are 5 more $60 bonds than $120 bonds
x = y + 5
by solving the system
x = y + 5
60*x + 120*y = 2100
we find
x = 15
y = 10
She has 15 bonds of $60 and 10 bonds of $120.