In this task, you need to provide the correct option for a given problem from the provided options.
--------
Question: Problem: the ratio of three numbers is 1 : 3 : 4 and the sum of their squares is 2600 . the sum of the numbers is ? 
Options: a ) a ) 10 , b ) b ) 12 , c ) c ) 15 , d ) d ) 14 , e ) e ) 9

Answer: a


Question: Problem: the duplicate ratio of 3 : 4 is ? 
Options: a ) 1 : 2 , b ) 1 : 4 , c ) 1 : 8 , d ) 9 : 16 , e ) 1 : 13

Answer: d


Question: Problem: the hcf of two numbers is 42 and the other two factors of their lcm are 10 and 20 . what is the largest number . 
Options: a ) 462 , b ) 450 , c ) 840 , d ) 504 , e ) 555

Answer:
c