Quantitative Aptitude - Arithmetic Ability Questions

From the top of a 20 m high building, the angle of elevation of the top of a tower is 60° and the angle of depression of it's foot is at 45°, then the height of the tower is (√3=1.732)

A triangular prism has 9 edges. How many vertices does it have?

If x = 999, y = 1000, z = 1001, then the value of x3+y3+z3-3xyzx-y+z is

What is the value of [(sin 7x – sin 5x)÷(cos 7x + cos 5x)] – [(cos 6x – cos 4x)÷(sin 6x + sin 4x)]?

The areas of two similar triangles ΔABC and ΔPQR are 36 sq cms and 9 sq cms respectively. If PQ = 4 cm then what is the length of AB (in cm)?

The average weight of P, Q and R is 71 kg. If the average weight of P and Q be 66 kg and that of Q and R be 76.5 kg, then the weight (in kg) of Q is.

If the sum of ten different positive integers is 100, then what is the greatest possible number among these 10 numbers?

By what fraction selling price (S.P.) must be multiplied to get the cost price (C.P.) if the loss is 20% ?