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

Problem: if 75 percent of a class answered the first question on a certain test correctly , 35 percent answered the second question on the test correctly , and 20 percent answered neither of the questions correctly , what percent answered both correctly ?
Options: a ) 10 % , b ) ( 8 ) 20 % , c ) 30 % , d ) 50 % , e ) 65 %
c

Problem: an urn contains 10 black and 5 white balls . two balls are drawn from the urn one after the other without replacement . what is the probability that both drawn balls are black ?
Options: a ) 1 / 5 , b ) 3 / 7 , c ) 2 / 5 , d ) 3 / 5 , e ) 2 / 7
b

Problem: the l . c . m . of 2 numbers is 30 . the numbers are in the ratio 2 : 3 . find their sum ?
Options: a ) 36 , b ) 25 , c ) 48 , d ) 32 , e ) 56
b