21. The greatest possible length which can be used to measure exactly the lengths 7 m, 3 m 85 cm, 12 m 95 cm is:

A. 15 cm

B. 25 cm

C. 35 cm

D. 42 cm

22. Three numbers which are co-prime to each other are such that the product of the first two is 551 and that of the last two is 1073. The sum of the three numbers is:

A. 75

B. 81

C. 85

D. 89

23. Find the highest common factor of 36 and 84.

A. 4

B. 6

C. 12

D. 18

24. Which of the following fraction is the largest?

25. The least number, which when divided by 12, 15, 20 and 54 leaves in each case a remainder of 8 is:

A. 504

B. 536

C. 544

D. 548