4th term of an AP

Algebra Level 2

If the 8 8 th term of an arithmetic progression is twice its 6 6 th term, what is the 4 4 th term of the arithmetic progression?


The answer is 0.

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.

2 solutions

Srinivasa Gopal
Mar 7, 2020

Let the initial term and the common difference of the AP be "a" and "d" respectively. Eighth term of an AP is a + 7d and its sixth term is a + 5d

a + 7d = 2*(a+5d) = 2a + 10d

a = - 3d -----(1)

Fourth term = a + 3d = 0 from (1)

a 8 = 2 ( a 6 ) a_8 = 2(a_6)

a 1 + 7 d = 2 ( a 1 + 5 d ) a_1 + 7d = 2(a_1 + 5d)

a 1 + 7 d = 2 a 1 + 10 d a_1 + 7d = 2a_1 + 10d

a 1 = 3 d a_1 = -3d

a 4 = a 1 + 3 d = 3 d + 3 d = 0 a_4 = a_1 + 3d = -3d + 3d = \boxed{0}

0 pending reports

×

Problem Loading...

Note Loading...

Set Loading...