In this task, you need to answer the given multiple-choice question on the gain. Gain is the value by which to multiply the input. Classify your answers into 'a', 'b', 'c', 'd', and 'e'.

Problem: by selling 16 pencils for a rupee a man loses 28 % . how many for a rupee should he sell in order to gain 28 % ? 
Options: a ) 8 , b ) 9 , c ) 7 , d ) 6 , e ) 4
b

Problem: a and b began business with rs . 3000 and rs . 4000 after 8 months , a withdraws rs . 1000 and b advances rs . 1000 more . at the end of the year , their profits amounted to rs . 630 find the share of a ? 
Options: a ) 240 , b ) 278 , c ) 209 , d ) 267 , e ) 262
a

Problem: solution x is 80 % chemical a and 20 % chemical b by volume . solution y is 50 % chemical a and 50 % chemical b by volume . if a mixture of x and y is 68 % chemical a , what percent of the mixture is solution x ? 
Options: a ) 20 % , b ) 25 % , c ) 30 % , d ) 35 % , e ) 40 %

e