Quantitative Aptitude - Arithmetic Ability Questions

If x+1x=5,then the value of x1+x+x2 is

Dealer purchased an article for Rs. 900 and fixes the list price in such a way that he gains 20% after allowing 10% discount, then the list price is

The average age of 19 boys in a class is 21 years. If the teacher's age is included, the average increases to 22 years. What is the teacher's age?

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

The average cost of 4 items in a shopping list is Rs 1,250. If one more item whose cost is Rs 2,000 is added to the list what will be the new average (in
Rs)?

Simple interest on a certain sum of money for 3 years at 8% per annum is half the compound interest on Rs. 16000 for 2 years at 10% per annum. The sum placed on simple interest is:

Choose the word is least like the other words in the group

What is the value of xy if x - y = 3 and x2+y2=15?