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 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:

If the roots of the equation a(b – c)x2 + b(c – a)x + c(a – b) = 0 are equal, then which of the following is true?

Select the odd word/letters/number/number pair from the given alternatives.

In the following question, four groups of three numbers are given. In each group the second and third number are related to the first number by a Logic/Rule/Relation. Three are similar on basis of same Logic/Rule/Relation. Select the odd one out from the given alternatives.

Select the odd word/letters/number/number pair from the given alternatives.

The diameter of a circle is 28 cm find its area?

The average revenues of 13 consecutive years of a company is Rs 70 lakhs. If the average of first 7 years is Rs 65 lakhs and that of last 7 years is Rs 77 lakhs, find the revenue for the 7th year.