Quantitative Aptitude - Arithmetic Ability Questions

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

What is the value of ( 1/3 + cosec30)?

When a number is increased by 42, it becomes 121% of itself. What is the number?

A solid right circular cone of radius 4 cm and height 7 cm is put inside a cylindrical vessel of radius 5 cm and height 8 cm. How much water in cubic cm will be required to fill the cylindrical vessel completely?

From a point P, the angle of elevation of a tower is such that its tangent is 3/4. On walking 560 metres towards the tower the tangent of the angle of elevation of the tower becomes 4/3. What is the height (in metres) of the tower?

If the shopkeeper sells an item at Rs 1600 which is marked as Rs 2000, then what is the discount he is offering?

Find out the odd word/letters/number/number pair from the given alternatives.