instruction:
In this task, you need to provide the correct option for a given problem from the provided options.
question:
Problem: how many kilograms of pure water is to be added to 100 kilograms of a 30 % saline solution to make it a 10 % saline solution . 
Options: a ) 100 , b ) 200 , c ) 300 , d ) 400 , e ) 500
answer:
b


question:
Problem: a certain university will select 2 of 6 candidates eligible to fill a position in the mathematics department and 3 of 5 candidates eligible to fill 2 identical positions in the computer science department . if none of the candidates is eligible for a position in both departments , how many different sets of 3 candidates are there to fill the 3 positions ? 
Options: a ) 42 , b ) 70 , c ) 150 , d ) 165 , e ) 315
answer:
c


question:
Problem: 180 college students were asked in a survey if they preferred windows or mac brand computers . 50 students claimed that they preferred mac to windows brand computers . one third as many of the students who preferred mac to windows , equally preferred both brands . 60 of the students had no preference . how many of the students in the survey preferred windows to mac brand computers ? 
Options: a ) 25 , b ) 70 , c ) 50 , d ) 60 , e ) 75
answer:

b