Question

7. Phozia has three pieces of rope with lengths of 160 cm, 192 cm and

240 cm respectively. She wishes to cut all three pieces of rope into
shorter pieces of equal length so that there is no left over rope.
(a) What is the largest possible length of each of the shorter pieces of
rope?
(b) How many shorter pieces of rope can she get altogether?​

Answer 1

a) 16 cm, b) 37 pieces

Explanation:

Part a

Finding the largest divisor of 160, 192 and 240

160 divisors: 1, 2, 4, 5, 8, 10, 16, 32, 40, 80 and 160.

// You can alternatively find them by factor pairs, which are (1, 160), (2, 80), (4, 40), (5, 32), (8, 20) & (10, 16). This way is much more faster. Also, you can simply search them in metanumbers.com

192 divisors: 1, 2, 3, 4, 6, 8, 12, 16, 24, 32, 48, 64, 96 and 192

240 divisors: 1, 2, 3, 4, 5, 6, 8, 10, 12, 15, 16, 20, 24, 30, 40, 48, 60, 80, 120 and 240

The largest divider that they all have in common is 16.

So 16 cm is the largest possible length of each of the shorter pieces of

rope

Part b

Now we have to count how many 16 cm pieces of rope can we get from the large rope pieces, which lengths are 160 cm, 192 cm and 240 cm

160/16 + 192/16 + 240/16 = 10 + 12 + 15 = 37

The answer is 37 pieces