Question

the fourth term of an AP is zero prove that 25th term of the ap is 3 times its 11th term

Answer 1

Hello,
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In an AP,

Fourth term = a + 4d = 0


a + 4d = 0

=> a = - 3d ......(i)

Now,

25th term = a + 24d

= - 3d + 24d [From (i)]

= 21d

and

11th term = a + 10d

= - 3d + 10d [From (i)]

= 7d

This, 21d is 3 times 7d.

Therefore,

25th term = 3 × 11th term

HOPE IT HELPS