Question

Rebecca had 9/10 of a yard of ribbon. Then she gave 7/20 of a yard to a friend. How much does she have left? Explain your work

Answer 1

Answer:
`(11)/(20)` yards

Explanation:

By considering the given information , we have

The total initial length of ribbon =
`(9)/(10)` yards

The length of ribbon she gave to her friend =
`(7)/(20)` yards

The length of ribbon she has left = Initial length - Length she gave

`=(9)/(10)-(7)/(20)`

`=(9*2)/(10*2)-(7)/(20)` [Multiply 2 on numerator and denominator to the first fraction to make both fractions like.]

`=(18)/(20)-(7)/(20)`

`=(18-7)/(20)=(11)/(20)`

hence, the length of ribbon she has left =
`(11)/(20)` yards

Answer 2

rewrite fraction s to have common denominator:

9/10 = 18/20

now subtract:

18/20 - 7/20 = 11/20 left