Answer:
n+2
Step-by-step explanation:
This is a Typical Question on Arithmetic Progression with initial term as 2n+1
The next number in this particular series will be 2n+1+2 which is 2n+3 and so on. Thus a common difference of 2 exists.
The nth term of an Arithmetic Progression AP, bn is represented below where b1 is the first term
bn=b1 +(n-1)d where d is the common difference
For this particular series, the 4th term b4 is
b4= 2n+1+(4-1)2 0r b4 =2n+1+6=2n+7
sum of series is represented by equation: n(b1 +b4)/2 where b1 and b4 are 1st and 4th term respectively
Thus Sum required =4(2n+1+2n+7)/2=4(4n+8)/2=8n+16 0r n+2
