CBSE Class 10CBSE
Share
Notifications

View all notifications

If five times the fifth term of an A.P. is equal to 8 times its eight term, show that its 13th term is zero - CBSE Class 10 - Mathematics

Login
Create free account


      Forgot password?

Question

If five times the fifth term of an A.P. is equal to 8 times its eight term, show that its 13th term is zero

Solution

Let a1 , a2 , a3 , ….. , an, …. be the A.P. with its first term = a and common difference = d.

It is given that 5a5 = 8a8

⇒ 5(a + 4d) = 8 (a + 7d)

⇒ 5a + 20d = 8a + 56d ⇒ 3a + 36d = 0

⇒ 3(a + 12d) = 0 ⇒ a + 12d = 0

⇒ a + (13 – 1) d = 0 ⇒ a13 = 0

  Is there an error in this question or solution?
Solution If five times the fifth term of an A.P. is equal to 8 times its eight term, show that its 13th term is zero Concept: Arithmetic Progression.
S
View in app×