1. ## Average

The average of 5 results is 46 and that of first 4 is 45.The fifth result is
(a)1
(b)10
(c)12.5
(d)50

2. Hello,
Originally Posted by devi
The average of 5 results is 46 and that of first 4 is 45.The fifth result is
(a)1
(b)10
(c)12.5
(d)50
The average of 5 results is given this way :

$A=\frac{a+b+c+d+e}{5}$, where a,b,c,d,e are the results. In general, you divide the sum of the results by the number of results.

We know that the sum of the first 4 is 45, let's say a+b+c+d=45 and that the average is 46.

$46=\frac{45+e}{5}$

Solve for e...

e+45=46
46-45=e
e=1