In this task, you need to answer the given multiple-choice question on the general math. Classify your answers into 'a', 'b', 'c', 'd', and 'e'.

Problem: the average weight of a , b , c is 45 kg . the avgwgt of a & b be 40 kg & that of b , c be 43 kg . find the wgt of b . 
Options: a ) 23 , b ) 43 , c ) 21 , d ) 31 , e ) 43
d

Problem: it takes 30 days to fill a laboratory dish with bacteria . if the size of the bacteria doubles each day , how long did it take for the bacteria to fill one sixteenth of the dish ? 
Options: a ) 16 days , b ) 26 days , c ) 27 days , d ) 28 days , e ) 29 days
b

Problem: a company charges a fixed rental of rs . 350 per month . it allows 200 calls free per month . each call is charge at rs . 1.4 when the number of calls exceed 200 per month and it charges rs . 1.6 when the number of calls exceeds 400 per month and so on . a customer made 150 calls in february and 250 calls in march . by how much percent each call is cheaper in march than each call in february . 
Options: a ) 28 % , b ) 25 % , c ) 18.5 % , d ) 16 % , e ) none of these

a