The average of 12 numbers is 15 and the average of the first two is 14. What is the average of the rest?

The body weight of seven students of a class is recorded as 54 kg, 78 kg, 43 kg, 82 kg, 67 kg, 42 kg and 75 kg. What is …

The average of 25 observations is 13. It was later found that an observation 73 was wrongly entered as 48. The new avera…

The average of runs of a cricket player of 10 innings was 32. How many runs must he make in his next innings so as to in…

Four years ago, the average age of a family of four persons was 18 years. During this period, a baby was born. Today if …

The average weight of five persons sitting in a boat is 38 kg. The average weight of the boat and the persons sitting in…

There are 4 consecutive odd numbers (x<sub>1</sub>, x<sub>2</sub>, x<sub>3</sub> and…

The average of 20 numbers is zero. Of them, at the most, how many may be greater than zero?