Question

Terri buys five and seven eighths ounces of chocolate chips. She uses four and four sixths ounces in a recipe. How many ounces of chocolate chips does she have left?

a one and ten forty eighths ounces
b one and three fourteenths ounces
c two and ten forty eighths ounces
d two and three fourteenths ounces

Answer 1

(A)
`1(10)/(48)`

Explanation:

To find how many chocolate chips are left, you have to subtract the amount used for the recipe from the original amount which is:

`5(7)/(8) -4(4)/(6)`

To subtract the two mixed numbers, first you have to convert them to improper fractions which would make the expression:

`(47)/(8)-(28)/(6)`

Then, in order to subtract the two improper fractions, since they have different denominators, you have to make them have the same denominator. The LCM (Least Common Multiple) of 8 and 6 is 24, so to subtract the two fractions, you need both of them to have a denominator of 24. That would make the expression:

`(141)/(24)-(112)/(24)`

To subtract these two fractions, since they have the same denominators, you can subtract the numerators and keep the denominators. That would make the answer:

`(29)/(24)` which is, as a mixed number,
`1(5)/(24)`, which is
`1(10)/(48)`.

Hope this helps :)