If the mean of x₁ and x₂ is 12.5 and mean of x₁, x₂ and x₃ is 16. The value of x₃ is :

1. 32

2. 3.5

3. 285

4. 23

Find the mean of 43, 51, 50, 57 and 54.

Find the mean of first ten odd natural numbers.

Find the mean of all factors of 10.