Quantitative Aptitude - Arithmetic Ability Questions

A bookseller bought 500 text books for  20,000. He wanted to sell them at a profit so that he get 50 books free. At what profit percent should he sell them?

Arrange the fractions 34,512,1316,1629,38 in their ascending order of their magnitude?

Line segment AB is parallel to line segment CD. AD intersects BC in E. If lengths of AE, BC and ED are 12 cm, 12 cm and 18 cm respectively, what is the length of EC?

The average marks obtained in a class of 50 students is 70%. The average of first 25 is 60% and that of 24 is 80%. What is the marks obtained by the last student?

If Sec θ = 25/24 , then what is the value of Sin θ?

If a - b = 1 and ab = 6, then what is the value of a3- b3?

If x+y+z = 1, 1/x + 1/y + 1/z = 1 and xyz = -1, then x3+y3+z3 is equal to

If x = 6+26, then what is the value of x-1 + 1x-1 ?