instruction:
In this task, you need to answer the given multiple-choice question on the general math. Classify your answers into 'a', 'b', 'c', 'd', and 'e'.
question:
Problem: average age of students of an adult school is 42 years . 120 new students whose average age is 32 years joined the school . as a result the average age is decreased by 4 years . find the number of students of the school after joining of the new students . 
Options: a ) 1200 , b ) 120 , c ) 360 , d ) 200 , e ) none of these
answer:
d


question:
Problem: two trains of equal length are running on parallel lines in the same directions at 46 km / hr . and 36 km / hr . the faster trains pass the slower train in 144 seconds . the length of each train is : 
Options: a ) 82 m , b ) 150 m , c ) 172 m , d ) 200 m , e ) none of these
answer:
d


question:
Problem: what is the tens digit of 6 ^ 20 ? 
Options: a ) 1 , b ) 3 , c ) 5 , d ) 7 , e ) 9
answer:

d