Question

Mean of 100 items is 49 . It was discovered that three items which should have been 60,70 and 80 were wrongly read as 40,20 and 50 respectively. The correct mean is

(a) 48

(b) 82

(c) 50

(d) 80

Answer 1

The sum of items

$\begin{array}{c}=49 \times 100-(40+20+50)+(60+70+80) \\=5000 \\\therefore \quad \text { Mean of } 100 \text { items }=\frac{5000}{100}=50\end{array}$

So, The correct option of this question will be (C).