Question

Find the a20 for 3 8 13 18 for this sequence

Answer 1

The twentieth term of the sequence is 98.

Explanation:

The given sequence is 3, 8 , 13, 18 , ...

Any given sequence is said to be in Arithmetic Progression, if the difference between any two consecutive terms is always same.

Now here :

Second term - First term = 8 - 3 = 5

and Third term - Second term = 13 - 8 = 5

since the difference (d) = 5 is same in both cases, the given sequence is an AP.

Now, general term of an AP is
`a_(n)  =  a+ (n-1) d`

Here, n = 20 and d =5 and a = 3

So,
`a_(20)  =  3+ (20-1) (5)` = 3 + 19(5) = 98

So, the twentieth term of the sequence is 98.