The average of 10 numbers is 40.2. Later it is found that two  numbers have been wrongly copied. The first is 18 greater than the actual number and the second number added is 13 instead of 31. Find the correct average.

16 children are to be divided into two groups A and B of 10 and 6 children. The average percent marks obtained by the children of group A is 75 and the average percent marks of all the 16 children is 76. What is the average percent marks of children of groups B?

When a plot is sold for Rs. 18,700, the owner loses 15%. At what price must the plot be sold in order to gain 15% ?

The average number of printing error per page in a'bod 512 pages is 4. If the total number of printing error ml first 302 pages is 1,208, the average number of printinget per page in the remaining pages is'

If he is able to sell only 1200 out of the 1500 watches he has made in the season, then in the season he has made a profit of:

Find the average of the following set of scores.746 1020 321 12 63 428 226 144

A pupil's marks were wrongly entered as 83 instead of 63. Due to that the average marks for the class got increased by half. The number of pupils in the class is:

A trader marked the price of his commodity so as to include a profit of 25%. He allowed discount of 16% on the marked price. His actual profit was;

The average age of husband, wife and their child 3 years ago was 27 years and that of wife and the child 5 years ago was 20 years. What is the present age of the husband?

The mean of 50 observations was 36. It was found later that an observation 48 was wrongly taken as 23. The corrected new mean is: