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'.

[EX Q]: Problem: at what rate percent per annum will the simple interest on a sum of money be 1 / 5 of the amount in 10 years ? 
Options: a ) 2 % , b ) 7 % , c ) 9 % , d ) 3 % , e ) 1 %
[EX A]: a

[EX Q]: Problem: shawn invested one half of his savings in a bond that paid simple interest for 2 years and received $ 550 as interest . he invested the remaining in a bond that paid compound interest , interest being compounded annually , for the same 2 years at the same rate of interest and received $ 605 as interest . what was the value of his total savings before investing in these two bonds ? 
Options: a ) $ 2,750 , b ) $ 5,500 , c ) $ 11,000 , d ) $ 22,000 , e ) $ 44,000
[EX A]: a

[EX Q]: Problem: in one alloy there is 12 % chromium while in another alloy it is 8 % . 15 kg of the first alloy was melted together with 40 kg of the second one to form a third alloy . find the percentage of chromium in the new alloy . 
Options: a ) 8.8 % , b ) 9 % , c ) 9.2 % , d ) 9.1 % , e ) 8.4 %
[EX A]:
d