Question

Kim finds a 1-meter tree branch and marks it off in thirds and fifths. She then breaks the branch along all the markings and removes one piece of every distinct length. What fraction of the original branch remains

Answer 1

Answer:

3/5

Step-by-step explanation:

We want to find the fraction of the original branch that remains, so we will assume a length of the branch in order to make our calculation easier.

Since Kim marks it off in thirds and fifths, let's find the least common multiple of 3 & 5.

Least common multiple of 3 & 5 is 15.

Thus,let's make the length of the branch to be 15-meter long.

Now, if the branch is 15 m long, considering the markings of thirds and fifths, the branch would be cut at:

3, 5, 6, 9, 10, 12 meters.

We are told that She then breaks the branch along all the markings and removes one piece of every distinct length. Thus;

Distinct lengths are;

3 metres

5 - 3 = 2 metres

10 - 9 = 1 meter

Total she removes = 3 + 2 + 1 = 6 meters.

Total remaining is;

15 - 6 = 9 meters

Expressing this as a fraction of the original branch gives:

9/15

Divide both numerator and denominator by 3 to get; 3/5