Quantitative Aptitude - Arithmetic Ability Questions

If sin ­- 5π/3 = x, then the value of x is

tan(A/2) is equal to

If a(x + y) = b(x - y) = 2ab, then the value of 2(x2 + y2)

ABC is a right angled triangle. ∠BAC = 90 deg and ∠ACB = 60 deg. What is the ratio of the circum radius of the triangle to the side AB?

If x = 1.1, then what is the value of 4x2 -4x + 1 ?

If the angle of elevation of the sun decreases from 45° to 30°, then the length of the shadow of a pillar increases by 60m. The height of the pillar is

The diagonal of a cube is 192 cm. Its volume in cm3 will be 

$$\begin{gathered} ∆ABC is similar to ∆PQR. If ratio of perimeters of ∆ABC and ∆PQR is 1:2 and \\ if PQ = 10 cm then what is the length of AB (in cm)? \end{gathered}$$