instruction:
In this task, you need to provide the correct option for a given problem from the provided options.
question:
Problem: a college has classes from 10 : 00 am until 1 : 40 pm . in this duration , there are 5 periods . if 5 minutes are provided between each period to leave one class and enter the next class , how many minutes long is each period ? 
Options: a ) 38 min , b ) 41 min , c ) 40 min , d ) 42 min , e ) 52 min
answer:
c


question:
Problem: find the compound ratio of ( 2 : 3 ) , ( 5 : 11 ) and ( 11 : 2 ) is 
Options: a ) 3 : 2 , b ) 2 : 1 , c ) 1 : 2 , d ) 4 : 5 , e ) 5 : 3
answer:
e


question:
Problem: solution a is 20 % salt and solution b is 70 % salt . if you have 30 ounces of solution a and 60 ounces of solution b , in what ratio could you mix solution a with solution b to produce 50 ounces of a 50 % salt solution ? 
Options: a ) 6 : 4 , b ) 6 : 14 , c ) 2 : 3 , d ) 4 : 6 , e ) 3 : 7
answer:

c