In this task, you need to provide the correct option for a given problem from the provided options.

Problem: in a class of boys and girls vikas ' s rank is 9 th and tanvi ' s rank is 17 th . vikas ' s rank among the boys in that class is 4 th from the top and 18 th from the bottom and tanvi ' s rank among the girls is 8 th from top and 21 st from bottom . in the order of rank , how many girls are there between tanvi and vikas ? 
Options: a ) 29 , b ) 8 , c ) 2 , d ) 4 , e ) 6
c

Problem: an alloy is to contain steel and iron in the ratio 5 : 2 . the iron required to be melted with 35 kg of steel is ? 
Options: a ) 12 kg , b ) 14 kg , c ) 15 kg , d ) 20 kg , e ) 18 kg
b

Problem: how many of the positive factors of 25 , 150 and how many common factors are there in numbers ? 
Options: a ) 2 , b ) 4 , c ) 3 , d ) 5 , e ) 1

c