Quantitative Aptitude - Arithmetic Ability Questions

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

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

A sphere of radius 5 cm is melted to form a cone with base of same radius. The height (in cm) of the cone is

What is the value of [(cos 3θ + 2cos 5θ + cos 7θ)÷(cos θ + 2cos 3θ + cos 5θ)] + sin 2θ tan 3θ?

An equilateral triangle of area 300 cm2 is cut from its three vertices to form a regular hexagon. Area of hexagon is what percent of the area of triangle?

Working 10 hours a day, Aman can complete a piece of work in 18 days. How many hours a day should he work so as to finish the work in 15 days?

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?

Breadth of a rectangle is equal to the diagonal of the square whose side is 2.5√2 cm. Ratio between length and breadth of rectangle is 3 : 1. Find the area of the rectangle (in cm2).