Quantitative Aptitude - Arithmetic Ability Questions

ABCD is a quadrilateral with AB = 9 cm, BC = 40 cm, CD = 28 cm, DA = 15 cm and angle ABC is a right –angel
What is the area of quadrilateral ABCD?

What is the value of tan150°?

What is the value of cot210°?

What is the value of cot 11π/6?

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

When [x + (1/x)] = 5, then what is the value of [x – (1/x)]?

What is the sum of the first 12 terms of an arithmetic progression if the 3rd term is -13 and the 6th term is -4?

A's salary was decreased by 50% and subsequently increased by 50%. How much percent does he lose?