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

Problem: the compound ratio of 1 : 3 , 3 : 2 and 4 : 5 ?
Options: a ) 1 : 9 , b ) 1 : 7 , c ) 1 : 2 , d ) 2 : 5 , e ) 1 : 4
d

Problem: there are 680 students in a school . the ratio of boys and girls in this school is 3 : 5 . find the total of girls & boys are there in this school ?
Options: a ) 425 , b ) 345 , c ) 375 , d ) 380 , e ) 400
a

Problem: compound x contains elements a and b at an approximate ratio , by weight , of 2 : 10 . approximately how many grams of element b are there in 300 grams of compound x ?
Options: a ) 54 , b ) 162 , c ) 250 , d ) 270 , e ) 322
c