How to Find Total Number of Terms of an Arithmetic Sequence using Nth term formula - ItsMyAcademy.comItsMyAcademy.com

# How to Find Total Number of Terms of an Arithmetic Sequence using Nth term formula

How to Find Total Number of Terms of an Arithmetic Sequence using Nth term formula

In previous video we learned to find the nth term of Arithmetic Progression using the nth term formula of arithmetic sequence.

Now in this lesson we are going to learn “How to Find Total Number of Terms of an Arithmetic Sequence using Nth term formula”

It’s also simple like the previous problems. In this video there are two problems. In both problems we have to find the total number of terms of the arithmetic progression.

So did you take your pen and notebook let’s start our lesson!

What we learn?
1. In first problem we were given an AP with first term (a), last term (l) , common difference (d) that we calculated, now we need to find the total number of terms.

To find so we have to apply the nth term formula of AP in last term (l), we don’t how much term or which term number is “l”. But we can find the value of “n” which will give us the total number of term in that Arithmetic Progression. Because the n indicates actually the last term.

2. Second problem is also just like the first problem.

I hope now you learnt how to find the total number of term in an arithmetic progression using nth term formula of Arithmetic Progression containing last term.

Try to solve these problems based on Nth term of Arithmetic Progressions. If you feel any problems please comment. I will get back to you!

Q1. How many term there are there in Arithmetic Progressions given below

i) 7, 10, 13, ………………. , 43

ii) -1, -5/6, -2/3, -1/2, ……..10/3

iii) 18, 15½, 13, ………………, -47

iv) 7, 13, 19, …………………, 205

Q2. The first term of an Arithmetic Progression is 5, the common difference is 3 and the last term is 80; find the number of terms.