### The mean of the first ten even natural number is-

A. 0 B. 10 C. 11 D. 12 Answer: Option C

### Solution(By Apex Team)

\begin{aligned}&\text{ Required mean }\\ &=\left(\frac{2+4+6+\ldots\ldots+20}{10}\right)\\ &=\frac{2 (1+2+\ldots\ldots+10)}{10}\\ &=\left(\frac{1}{5}\times\frac{10\times11}{2}\right)\\ &\ left[\because1+2+3+\ldots+n=\frac{n(n+1)}{2}\right]\\ &=11\end{aligned}

## Related Questions On Average

A. 20
B. 21
C. 28
D. 32

A. 18
B. 20
C. 24
D. 30

A. 10 years
B. 10.5 years
C. 11 years
D. 12 years

### If the arithmetic mean of 0, 5, 4, 3 is a, that of -1, 0, 1, 5, 4, 3 is b and that of 5, 4, 3 is c, then the relation between a, b, and c is.

A. a = b = c
B. a : b : c = 3 : 2 : 4
C. 4a = 5b = c
D. a + b + c = 12