Question

What is the length of the longest rope which can be used to exactly measure 65cm and 115 cm?

• A. 5 cm
• B. 15 cm
• C. 25 cm
• D. 35 cm

Answer 1

The correct option is A

5 cm

The length of the longest rope to measure 65cm and 115 cm is basically the greatest number which would completely divide 65 and 115 i.e. the HCF of 65 and 115.

65= 5 $\times$ 13

115= 5 $\times$ 23

HCF= 5

Thus, maximum 5cm rope can be used to measure both 65cm and 115 cm exactly.