Quantitative Aptitude - Arithmetic Ability Questions

If x = [1/(√5 + √3)], y = [1/(√7 + √5)] and z = [1/(√7 + √3)], then what is the value of (x + y + z)?

The total surface area of a hemisphere is 4158 cm2. Find its diameter (in cm).

Three consecutive integers form the lengths of a right-angled triangle. How many sets of such three consecutive integers is/are possible?

A car travels from A to B with 40 Km/h and returns from B to A with 60 Km/h. Its average speed during the whole journey is

The distance between two pillars is 120 metres. The height of one pillar is thrice the other. The angles of elevation of their tops from the midpoint of the line connecting their feet are complementary to each other. The height (in metres) of the taller pillar is (Use : √3 = 1.732)

The mean of 100 observations was calculated as 40. It was found later on that one of the observations was misread as 83 instead of 53. The correct mean is:

Rohan borrowed a certain sum of money at simple interest. Rate of interest was 3% per annum for first 3 years, 4% per annum for next 5 years and 6% per annum for next 7 years. If he paid Rs 2059 as interest, then what is the sum borrowed (in Rs)?

Naveen purchased a gas cylinder and a stove for Rs.4500. He sold the gas cylinder at a gain of 25% and the stove at a loss of 20%, still gaining 4% on the whole. Find the cost of the gas cylinder.