Question

Which Term of an A.P : 3,8,13,18,…… is 78 ?

Answer 1

Answer:

Hence 78 is 16th term of the A.P

Refer to the attachment.

Step-by-step explanation:

Hope it helps you out.....

Answer 2

✬ 16th Term ✬

Step-by-step explanation:

Given:

• A.P series is 3 , 8 , 13 , 18 ....78.

To Find:

• Which term of a.p is 78?

Solution: Let nth term of A.P be 78.

Here, in this A.P series we have

• First term (a) = 3
• Common difference (d) = 8 – 3 = 5

As we know that an A.P series is given by

★ A^n = a + ( n – 1 ) d ★

Putting the values

$\implies{\rm }$ 78 = a + ( n – 1 ) d

$\implies{\rm }$ 78 = 3 + ( n – 1 ) 5

$\implies{\rm }$ 78 = 3 + 5n – 5

$\implies{\rm }$ 78 = –2 + 5n

$\implies{\rm }$ 78 + 2 = 5n

$\implies{\rm }$ 80 = 5n

$\implies{\rm }$ 80/5 = n

$\implies{\rm }$ 16 = n

Hence, the 16th term of A.P is 78.