Quantitative Aptitude - Arithmetic Ability Questions

The average of marks of 17 students in an examination was calculated as 71. But it was later found that the mark of one student had been wronglyentered as 65 instead of 56 and another as 24 instead of 50. The correct average is

The standard deviation of the set {10, 10, 10, 10, 10} is

Manoj can do a piece of work in 42 hours. If he is joined by Jayashree who is 100% more efficient, in what time they will finish the work together?

A can do a work in 36 days and B in 12 days. If they work on it together for 3 days, then what fraction of work is left?

An engineering student has to secure 36% marks to pass. He gets 53 and fails by 37 marks. Find the maximum marks.

Marked price of an item is Rs 200. On purchase of 1 item discount is 5%, on purchase of 2 items discount is 14%. Rajeshri buys 3 items, what is the effective discount? 

If the selling price of an item is Rs 1000 after getting a discount of 20%, then what was the marked price (in Rs)?

When a number is increased by 24, it becomes 110% of itself. What is the number?