If the average of 6 consecutive odd numbers is 30, the difference between the largest and the smallest numbers is:

Correct option is C

Given:

The average of 6 consecutive odd numbers is 30.

Solution: 

Average of 6 consecutive odd number is equal to the average of third and fourth odd number,

Let third number = x₃ and fourth number = x₄ 

x₄ = x₃ + 2 ( odd number) 

so, 

$$\frac{x_3 + x_4}{2} = 30\\ \ \\x_3 + x_4 = 60\\ \ \\x_3 + (x_3 + 2) = 60\\ \ \\2x_3 + 2 = 60\\ \ \\2x_3 = 58\\ \ \\x_3 = 29$$​

25, 27, 29, 31, 33, 35

The smallest number is 25

The largest number is 35

35 - 25 = 10