Question

Find the number of terms in the series 11,6,1,...,54

Answer 1

Answer:-

14 terms

Explanation:-

Given

series is-

11, 6, 1... -54

To Find

No. of terms in the series

Solution

The series is

11, 6, 1...., 54

Here,

common diff. (d) is,

$a_{2}-a_{1} = a_{3} - a_{2}$

$6-11 = 1-6$

$-5 = -5$

Since, the common diff. is equal!

The given series is in A.P.

we have,

a = 11

d = -5

$a_{n}$= -54

From the nth term Foumulae

$\boxed{a_{n} = a+(n-1)d }$

$-54 = 11+(n-1)(-5)$

$-54 = 11 -5n + 5$

$-54 = 16-5n$

$-5n = -54-16$

$\cancel{-}5n = \cancel{-}70$

$n = \dfrac{70}{5}$

$n = 14$

Hence, there are 14 terms in the A.P.

Answer 2

Answer:

ur question should be

Find the number of terms in the series

11,6,1........-54

refer the attachment for the answer