Question

The mean of $27$ observations is $35$. If $5$ is subtracted from each observation, what will be the new mean?

• A. $28$
• B. $30$
• C. $32$
• D. $34$

Answer 1

The correct option is B $30$

mean of $27$ observations = $35$
Sum of $27$ observations = $35\times 27$ = $945$
If $5$ is subtracted from all the observations,
Sum of $27$ observations = $945-27\times 5$ = $810$
New Mean = $\frac{810}{27}$ = $30$