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: radha bought a watch for rs . 144 and got a percentage of profit equal to the cost price of the watch . what is the cost price of the watch ? 
Options: a ) rs . 72 , b ) rs . 78 , c ) rs . 80 , d ) rs . 90 , e ) rs . 92
[EX A]: d

[EX Q]: Problem: if rs . 420 amount to rs . 540 in 4 years , what will it amount to in 6 years at the same rate % per annum ? 
Options: a ) s . 575 , b ) s . 595 , c ) s . 590 , d ) s . 600 , e ) s . 585
[EX A]: d

[EX Q]: Problem: find the c . i . on a sum of rs . 10000 for 9 months at 20 % per annum , interest being compounded quarterly ? 
Options: a ) 2000 , b ) 10025 , c ) 1025 , d ) 2015 , e ) 2025
[EX A]:
c