A set of 15 numbers has mean 42. Mean of first 8 is 39 and last 8 is 44. Value of eighth number?

If M is the mean of the first 100 even natural numbers, then what is the mean of the first 100 odd natural numbers?

The average marks of 13 papers are 40. Average of first 7 is 42 and last 7 is 35. Marks obtained in the 7th paper are

The average of 6 numbers is 5. The first number is increased by 2, second by 4, third by 8 and so on. The average of new numbers is

If x is the average of 1², 2², 3², ..., 10² and y is the average of first 10 even natural numbers, then y is what percent of x − y?

Average of 13 results is 65, if the average of first seven results is 62 and the average of last seven results is 67, then the seventh result is :