The mean of ten positive numbers is 16. When another number is added, the mean becomes 18. Find the eleventh number
Two numbers are removed at random from the numbers 1, 2, 3 and 4. What is the probability that the sum of the numbers removed is even?
Find the probability that a number selected at random from 41 to 56 is a multiply of 9
Which of the following is in descending order?