TASK DEFINITION: Given a math problem with context and a question and 5 answer choices, the task is to provide the correct answer choice based on the problem. You must choose one of the given answer choices by letter: a, b, c, d, or e; anything else is invalid.
PROBLEM: Problem: the average weight of a group of persons increased from 48 kg to 51 kg, when two persons weighing 78 kg and 93 kg join the group. find the initial number of members in the group ?
Options: a. 87, b. 67, c. 23, d. 75, e. 25

SOLUTION: c

PROBLEM: Problem: what is the units digit of ( 3 ^ 13 ) ( 4 ^ 13 ) ?
Options: a. 2, b. 4, c. 6, d. 7, e. 8

SOLUTION: a

PROBLEM: Problem: for 2 consecutive yrs, my incomes are in the ratio of 4: 7 and expenses in the ratio of 3: 5. if my income in the 2 nd yr is rs. 42000 & my expenses in the first yr in rs. 20000, my total savings for the two - year is
Options: a. s. 8000, b. s. 9000, c. s. 9900, d. s. 9990, e. s. 11000

SOLUTION:
e