Quantitative Aptitude - Arithmetic Ability Questions

On Selling a book at 9/14 of the marked price there is loss of 10%. What will be the ratio of marked price and cost price of the book?

The sum of digits of a two-digit number is 9. When the digits are reversed, the number decreases by 45. Find the changed number.

Find the volume (in cm3) of a cube of side 7.5 cm.

$$\begin{gathered} If (x – 2)2 + (y + 3)2 + (z – 15)2 = 0, then what is the value of \\ x + y + z – 5? \end{gathered}$$

3cosA is equal to

The angles of elevation of top and bottom of a flag kept on a flag post from 30 metres distance, are 45 and 30 deg respectively. Height of the flag is [taking √3 = 1.732]

A = (x8 – 1)/(x4 + 1) and B = (y4 – 1)/(y2 + 1). If x = 2 and y = 9, then what is the value ofA2 + 2AB + AB2?

What is the value of sec 4π/3?