M3L7 Application problem

Question

Jane found money in her pocket. She went to a convenience store and spent 1/4 of her money on chocolate milk, 3/5 of her money on a magazine, and the rest of her money on candy. What fraction of her money did she spend on candy?

Answer 1

So to solve this one we are going to say she found 100% of the money in her pocket (this can be written as 1/1), we will take this money and subtract the fractions she spent elsewhere:

1/1 - 1/4 - 3/5 = (money she spent on candy)

we need to make all these fractions have the same denominator so we will cross multiply by the denominators to put them all under one fraction:

1*4*5/(1*4*5) - 1*1*5/(1*4*5) - 3*1*4/(1*4*5) now lets calculate these all out: 20/20 - 5/20 - 12/20

now lets put the numerators all under the same denominator:

(20-5-12)/20 = 3/20

Jane spent 3/20 of the money she found in her pocket on candy