Problema Solution
Marie bought a total of 39 sweatshirts for her soccer team spending a total of $285. Some sweatshirts were large, the rest small. If the large sweatshirts cost $9 each and the small sweatshirts cost $7 each, how many large sweatshirts did she buy?
Answer provided by our tutors
Given:
total number of sweatshirts bought=39
total expenses=$285
cost of large sweatshirts=$9
cost of small sweatshirts=$7
find:
total number of large sweatshirts Marie bought
This problem can be solved by using two variables and two equations.
Let x=number of large sweatshirts bought
y=number of small sweatshirts bought
The two equationsare the following:
x+y=39
9x+7y=285
We can solve these equations by the substitution method:
x+y=39
y=39-x
9x+7y=285
9x+7(39-x)=285
9x+273-7x=285
9x-7x=285-273
2x=12
x=6
y=39-6
y=33
Marie bought 6 large sweatshirts and 33 small sweatshirts.