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: a boat having a length 8 m and breadth 2 m is floating on a lake. the boat sinks by 1 cm when a man gets on it. the mass of the man is :
Options: a. 12 kg, b. 60 kg, c. 72 kg, d. 160 kg, e. none of these
d

Problem: a fort had provision of food for 150 men for 45 days. after 10 days, 25 men left the fort. find out the number of days for which the remaining food will last.
Options: a. 44, b. 42, c. 40, d. 38, e. 36
b

Problem: anand finishes a work in 7 days, bittu finishes the same job in 8 days and chandu in 6 days. they take turns to finish the work. anand on the first day, bittu on the second and chandu on the third day and then anand again and so on. on which day will the work get over ?
Options: a. 3 rd, b. 6 th, c. 9 th, d. 7 th, e. 8 th

d