38
How many terms of the series " 1 + 2 + 3..........." add upto 5050
- A50
- B51
- C100
- D101
Answer not set
Log in or create a free account to reply and vote.
0
CCommunity
Answer for this question is option 3
0
CCommunity
Let the number of terms be n.
1 + 2 + 3 + ..... +n = 5050
$\frac{n(n+1)}{2}=5050$
n (n + 1) = 10100 [or use splitting
middle term method]
= 100 × 101
n (n + 1)=100 (100 + 1)
n = 100
1 + 2 + 3 + ..... +n = 5050
$\frac{n(n+1)}{2}=5050$
n (n + 1) = 10100 [or use splitting
middle term method]
= 100 × 101
n (n + 1)=100 (100 + 1)
n = 100