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: joe ' s average ( arithmetic mean ) test score across 4 equally weighted tests was 35 . he was allowed to drop his lowest score . after doing so , his average test score improved to 40 . what is the lowest test score that was dropped ?
Options: a ) 20 , b ) 25 , c ) 55 , d ) 65 , e ) 80
answer:
a

question:
Problem: 123 : 36 : : 221 : ?
Options: a ) 52 , b ) 69 , c ) 72 , d ) 25 , e ) 32
answer:
d

question:
Problem: how many kg of pure salt must be added to 100 kg of 10 % solution of salt and water to increase it to a 20 % solution ?
Options: a ) 6.7 , b ) 1.3 , c ) 9.6 , d ) 12.5 , e ) 7.9
answer:
d