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: A leak in the bottom of a tank can empty the full tank in 6 hours. An inlet pipe fills water at the rate of 4 liters per minute. When the tank is full in inlet is opened and due to the leak the tank is empties in 8 hours. The capacity of the tank is?

 Option A: 5768

 Option B: 5760

 Option C: 5762

 Option D: 5766

 Option E: 5712
Option B

Question: All of the citizens of a country have a six-character or seven-character national identification code that is created using the 26 letters of the alphabet and the 10 digits from 0 to 9. What is the maximum number of citizens who can be designated with these codes?

 Option A: 36^13

 Option B: 35(36^7

 Option C: 37(36^6

 Option D: 35(36^6

 Option E: 37(36^7
Option C

Question: A, B and C can do a piece of work in 20, 30 and 60 days respectively. In how many days can A do the work if he is assisted by B and C on every third day?

 Option A: 12 days

 Option B: 15 days

 Option C: 16 days

 Option D: 18 days

 Option E: 20 days

Option B