TASK DEFINITION: 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: Problem: at what rate percent per annum will the simple interest on a sum of money be 4 / 5 of the amount in 10 years ? 
Options: a ) 4 % , b ) 7 % , c ) 8 % , d ) 3 % , e ) 1 %

SOLUTION: c

PROBLEM: Problem: if 15 % of 40 is greater than 25 % of a number by 2 , the number is 
Options: a ) 14 , b ) 16 , c ) 18 , d ) 20 , e ) 22

SOLUTION: b

PROBLEM: Problem: a watch was sold at a loss of 10 % . if it was sold for rs . 140 more , there would have been a gain of 5 % . what is the cost price ? 
Options: a ) s . 933.33 , b ) s . 1009 , c ) s . 1007 , d ) s . 1006 , e ) s . 1002

SOLUTION:
a