Question

Which term of the A.P 21,18,15.......is -
-81

Answer 1

Step-by-step explanation:

21, 18, 15.....is zero? Hence, eighth term is zero. 00 logs are stacked in the following manner : 20 logs in the bottom row, 19 in the next row, 18 in the row next to it and so on

please mark as brianliest

Answer 2

Here,

a = 21

b = 18-21 = -3

$a_{ n} = - 81$

We have to find n

As,

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

$= > - 81 = 21 + (n - 1)( - 3)$

$= > - 81 = 24 - 3n$

$= > - 105 = - 3n$

So,

n = 35

Therefore, the 35 terms of the given A.P is -81.

$e$

Next,we want to know if there is any n for which

$a_{n} = 0$

If such n is there ,then

$21 + (n - 1)( - 3) = 0$

$3(n - 1) = 21$

$n = 8$

So, the eighth term is 0.

$1$

❄︎ Good luck ❄︎