Question

4) In an AP. the first termis-5 and last term is 45. If sum of all numbers in the AP. le 120,
then how many terms are there in AP.​

Answer 1

Step-by-step explanation:

is a is equal to 5 and a n that is the last term is 45 and then sum of all numbers is 120

Answer 2

Answer:

6

Step-by-step explanation:

a = -5 ; l = 45

$S_{n} = \frac{n}{2} [a+l]$

$120 = \frac{n}{2} [-5+45]$

$n = \frac{(120)(2)}{40}=6$

Therefore, there are 6 terms in the A.P

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