An algebra problem by Srutarshi Chakrabarti

Algebra Level 2

Find the value of 1X2+2X3+3X4+...................nX(n+1)

{n (n+1) (n+2)}/3 n n^3 n (n+1) (2n+1)/6 n(n+1)/6

1 solution

Sakanksha Deo
Feb 8, 2015

I think the answer should be n (n+1) (n+2)/6

no it won't be see book S.N.Dey class 11 Sequence and Series

Srutarshi Chakrabarti - 6 years, 4 months ago

Bro....don't be a bookworm.it can have misprints.

Just put n = 2

Then,

According to question

Answer should be 2

But by your answer it is 5

Try it!

Sakanksha Deo - 6 years, 4 months ago

Ya you are right the question I have given is a wrong one thanks for pointing me out.

Srutarshi Chakrabarti - 6 years, 4 months ago

@Srutarshi Chakrabarti – You are welcome bro.......i don't think there is any problem with the question....just edit the answer

Sakanksha Deo - 6 years, 4 months ago

@Sakanksha Deo – no watch the edited one its alright now

Srutarshi Chakrabarti - 6 years, 4 months ago