The mean age of n men in a club is 50 years. Two men aged 55 and 63 years left the club, and the mean age reduced by 1 year. Find the value of n.
A committee of 4 is to be selected from a group of 5 men and 3 women. In how many ways can this be done if the chairman of the committee must be a man?
Which of the following is a singular matrix?
Simplify \(8^{n} \times 2^{2n} \div 4^{3n}\)
