Quantitative Aptitude - Arithmetic Ability Questions

The average age of 40 students of a class is 16 years. If the average age of 24 students is 15.5 years and that of the 15 students is 16 2⁄3 years, then the age of 40th student is

The sum of the ages of husband and wife at present is 60. Four years ago the ratio of their ages was 7:6. What is the age of the husband?

The mean of 10 observations is 13. Two more observations are included and the new mean becomes 14. The mean of two new observations is

Find out the odd word/letters/number/number pair from the given alternatives.

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

In an army selection process, the ratio of selected to unselected was 5:1. If 100 less had applied and 20 less selected, the ratio of selected to unselected would have been 6:1. How many candidates had applied for the process?

If [√(a2 + b2 + ab)] + [√(a2 + b2 – ab)] = 1, then what is the value of (1 – a2 )(1 – b2 )?