Of the three numbers, the first is twice the second and the second is twice the third. The average of the reciprocal of …

The average expenditure of a man for the first five months of a year is Rs. 5000 and for the next seven months it is Rs.…

The mean high temperature of the first four days of a week is 25°C whereas the mean of the last four days is 25.5&de…

If the average marks of three batches of 55, 60 and 45 students respectively is 50, 55, 60, then the average marks of al…

The average weight of 15 students in a class increases by 1.5 kg when one of the students weighing 40 kg is replaced by …

Find the average of cubes of first 49 positive integers.

Mean of 10 numbers is 30. Later on it was observed that numbers 15, 23 are wrongly taken as 51, 32. The correct mean is …

The captain of a cricket team of 11 members is 26 years old and the wicket keeper is 3 years older. If the ages of these…