Quantitative Aptitude - Arithmetic Ability Questions

Which one of the following is an irrational number?

What is the value of Sin 30° - Cosec 45°?

The area of a right angled triangle ABC, right angled at B, is 46 sq units. A median is drawn from A to BC which intersects at D. Find the area (in sq. units)of triangle ABD.

In what ratio is the segment joining (12,­1) and (-­3,4) divided by the Y­-axis?

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

A, B and C can do a job working alone in 6, 9 and 18 days respectively. They all work together for 1 day, then A and B quit. How many days C working alone will take to complete the remainder of the job?

Among four students sitting in a row, average age of last three students is 20 years and the average age of first three students is 21 years. If the age of first student is 26 years, then what is the age (in years) of the last student?

Find the mean value of 2, 3, 3, 4, 6, 7