If the median of observations 12, 1, 8, 54, 61, 28, 45, 35, 21, 17 is M, then what is the value of 2M + 5?

The arithmetic mean of 100 observations is 50. If 10 is added to each observation then what will be the new arithmetic mean?

What is the median of all possible factors of 120 ?

The value of a 2-digit number is 5 times the sum of the digits. What is the product of the digits ?

Let m and n be natural numbers. What is the minimum value of (m + n) such that 33m + 22n is divisible by 121?

What is the LCM of 3·6, 0·009, 0·27?