### The average of 9 observations was found to be 35. Later on, it was detected that an observation 81 was misread as 18. The correct average of the observation is.

A. 28 B. 42 C. 32 D. 45 Answer: Option B

### Solution(By Apex Team)

$\begin{array}{l}\text{Difference = 81 – 18 = 63}\\ \text{So, change in average}\\ =+\frac{63}{9}\\ \text{ = + 7}\\ \text{Correct average = 35 + 7}=42\end{array}$

## 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