Exercise 1

The average of two numbers is XY. If one number is X, the other is

There are five boxes in a cargo hold. The weight of the first box is 200 kg and the weight of the second box is 20% more than the weight of the third box, whose weight is 25% more than the first box’s weight the fourth box at 350 kg is 30% lighter than the fifth box. The difference in the average weight of the four heaviest boxes and the four lightest boxes is

In Kiran’s opinion, his weight is greater than 65 kg but less than 72 kg. his brother does not agree with Kiran and he think that kiran’s weight is greater than 60 kg but less than 70 kg. His mother’s view is that his weight cannot be greater than 68 kg. if all of them are correct in their estimation, what is the average of different probable weights of Kiran ?

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

The mean of the first ten even natural number is

The arithmetic mean of first 11 natural numbers is

Find the average of all the numbers between 6 and 34 which are divisible by 5.

The average of the first five multiples of 3 is

The average of the first nine prime numbers is

A student was asked to find the arithmetic mean of the numbers 3, 11, 7, 9, 15, 13, 8, 19, 17, 21, 14 and x. He found the mean to be 12. What should be the number in place of x ?