You are given a math word problem and you are supposed to make use of mathematical concepts like probability, combinatorics, linear equations, sequences/series, or simple operators like addition, subtraction, division, or multiplication to answer the given question. Choose the best option from the 5 given options and report that option.

Question: Three persons invested Rs.9000 in a joint business. The second person invested Rs.1000 more than the first and the third Rs.1000 more than second. After two years, they gained Rs.5400. How much third person will get?

 Option A: Rs.2400

 Option B: Rs.3600

 Option C: Rs.2850

 Option D: Rs.2000

 Option E: Rs.3000
Option A

Question: Read the following three equations:
5 ~ 4 ~ 3 ~ 9 = 4215
6 ~ 9 ~ 2 ~ 6 = 3816
4 ~ 7 ~ 3 ~ 3 = 1122
Now based on the rule that has been used, solve the following equation:
4 ~ 2 ~ 7 ~ 4 = ____

 Option A: 1416

 Option B: 2910

 Option C: 2940

 Option D: 3749

 Option E: 4470
Option A

Question: The least perfect square, which is divisible by each of 21, 36 and 66 is:

 Option A: 213444

 Option B: 214344

 Option C: 214434

 Option D: 231444

 Option E: 23444

Option A