A.P.

Algebra Level 3

If S n = n P + 1 2 n ( n − 1 ) Q S_n = nP + \frac{1}{2} n (n - 1)Q , when S n S_n denotes the sum of the first n terms of an A.P. , then the common difference is

2Q Q 2P + 3Q P + Q

Sakanksha Deo by Sakanksha Deo , 23, India

This section requires Javascript.
You are seeing this because something didn't load right. We suggest you, (a) try refreshing the page, (b) enabling javascript if it is disabled on your browser and, finally, (c) loading the non-javascript version of this page . We're sorry about the hassle.

1 solution

Marissa Chong
Mar 24, 2015

S n = n / 2 [ 2 a + ( n − 1 ) d ] Sn\quad =\quad n/2[\quad 2a\quad +\quad (n-1)d\quad ]

S n = n a + n / 2 ( n − 1 ) d Sn\quad =\quad na\quad +\quad n/2(n-1)d

a = 1st term and d = common difference. Hence, P = a and Q =d therefore the answer is Q.

3 Helpful 0 Interesting 0 Brilliant 0 Confused

Nice solution! Cool! Thanks...

Sajjad Sajjad - 6 years, 2 months ago

0 pending reports

×

Problem Loading...

Note Loading...

Set Loading...