Sanjay wants to exactly measure the lengths 7000 mm, 3850 mm and 12950 mm using a single measuring tape. What will be the greatest possible length (in cm) of the measuring tape?

Correct option is C

$$7000 mm=700 cm \\3850 mm= 385cm \\12950 mm =1295cm\\700=2^2×5^2×7\\385=5×7×11\\1295=5×7×37\\$$​

The highest common factor (HCF) is $5\times 7=35$.