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: jerry went to a shop and bought things worth rs . 25 , out of which 30 $ went on sales tax on taxable purchases . if the tax rate was 6 % , then what was the cost of the tax free items ? 
Options: a ) 19 , b ) 19.7 , c ) 21.3 , d ) 21.5 , e ) 21.7

SOLUTION: b

PROBLEM: Problem: a total of $ 20,000 was invested in two certificates of deposit at simple annual interest rates of 3 percent and 6 percent , respectively . if the total interest on the two certificates was $ 1,440 at the end of one year , what fractional part of the $ 20.000 was invested at the higher rate ? 
Options: a ) 3 / 8 , b ) 21 / 25 , c ) 1 / 2 , d ) 3 / 5 , e ) 3 / 4

SOLUTION:
b