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: the average age of 7 men increases by 4 years when two women are included in place of two men of ages 26 and 30 years . find the average age of the women ? 
Options: a ) 42 , b ) 40 , c ) 30 , d ) 18 , e ) 11
answer:
a


question:
Problem: for any positive integer n , the sum of the first n positive integers equals n ( n + 1 ) / 2 . what is the sum of all the integers between 1 and 50 ? 
Options: a ) 1275 , b ) 1542 , c ) 985 , d ) 1024 , e ) 1125
answer:
a


question:
Problem: 4 , 25,49 , 
Options: a ) 149 , b ) 169 , c ) 189 , d ) 209 , e ) 121
answer:

e