Quantitative Aptitude - Arithmetic Ability Questions

A cistern has one inlet, L and one inlet, M. L takes 5 hours to fill the empty tank, when M is not open and M takes 8 hours to empty the full tank, if the tank is two fifth full, how much time will it take to fill the tank completely when both L and M are opened simultaneously? (in hours)

In the following question, select the odd number from the given alternatives.

A can finish a work in 7 days . B can finish the same work in 9 days . The days required to finish the work by both of them together.

The sum of length, breadth and height of a cuboid is 22 cm and the length of its diagonal is 14 cm.
If S is sum of the cubes of the dimensions of the cuboid and V is its volume, then what is (S-3V) equal to?

A sum of money was invested at the rate of 7.5% S.I. per annum for 4 years. If the investment was for 5 years, the interest earned would have been Rs. 375 more. What was the initial sum invested?

A sphere of radius 21 cm is cut into 8 identical parts by 3 cuts (1 cut along each axis). What will be the total surface area (in cm2) of each part?

A can do 75% of a job in 18 days and B can do 25% of the job in 12 days. If they work on it together, in how many days can they do 75% of the job?

If A = (-14 + 4) and B = 4 - 14, then AB =