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

Problem: if 30 % of the 880 students at a certain college are enrolled in biology classes , how many students at the college are not enrolled in a biology class ?
Options: a ) 620 , b ) 630 , c ) 616 , d ) 600 , e ) 650
c

Problem: a ratio between two numbers is 4 : 5 and their l . c . m . is 200 . the first number is
Options: a ) 60 , b ) 40 , c ) 20 , d ) 15 , e ) none
b

Problem: a bottle contains a certain solution . in the bottled solution , the ratio of water to soap is 3 : 2 , and the ratio of soap to salt is five times this ratio . the solution is poured into an open container , and after some time , the ratio of water to soap in the open container is halved by water evaporation . at that time , what is the ratio of water to salt in the solution ?
Options: a ) 1 : 1 , b ) 2 : 3 , c ) 3 : 2 , d ) 9 : 4 , e ) 45 : 8
e