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: 


23. 
Three numbers which are coprime 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: 


24. 
The least number, which when divided by 12, 15, 20 and 54 leaves in each case a remainder of 8 is: 

