Question
Mathematics Question on Sum of First n Terms of an AP
If Sn=3+7+11.... upto n terms and 40<n(n+1)6k=1∑nSk<45. Then n is
A
9
B
10
C
11
D
12
Answer
9
Explanation
Solution
The correct option is (A): 9
If Sn=3+7+11.... upto n terms and 40<n(n+1)6k=1∑nSk<45. Then n is
9
10
11
12
9
The correct option is (A): 9