Quantitative Aptitude - Arithmetic Ability Questions

The average revenues of 13 consecutive years of a company is Rs 78 lakhs. If the average of first 7 years is Rs 73 lakhs and that of last 7 years is Rs 85 lakhs, what is the revenue for the 7th year?

In the following question, select the missing number from the given series.1 108, 81, 54, 27, ?

ABCD is a quadrilateral with AB = 9 cm, BC = 40 cm, CD = 28 cm, DA = 15 cm and angle ABC is a right –angel. 
What is the area of triangle ADC?

How many balls of radius 2 cm can be made by melting a bigger ball of diameter 16 cm? (Take π = 22/7)

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?

The value of -3+3+87+43 is

What is the value of cot210°?

The value of (1 - √2) + (√2 - √3) + (√3 - √4) + ..... + (√15 - √16) is