Question

Natasha is cutting up rope.

She has 900 cm of rope.
Natasha uses 1/5 of the rope to tie up a parcel.
She uses 1/3 of the rope for a craft project.
What fraction of the original rope remains?
Give your answer as a fraction in its simplest form.

Answer 1

Answer is 7/15 rope remains

We know we start with 900 cm of rope

We know we use 1/5 and 1/3 of the rope

Let’s add 1/5 and 1/3 by finding the lowest common denominator - it’s 15

1/5 = 3/15

1/3 = 5/15

Total 8/15 used of 900 cm

Subtract 8/15 from the whole 15/15

(15/15 is one whole with a common denominator)

15 /15 - 8/15 = 7/15 rope remains