Question

which term of the ap .3,8,13,18,...is 78​

Answer 1

Answer:

16th term =78

Step-by-step explanation:

78=3+(n-1)5

n=16

Answer 2

$\bf{Question}$

Which term of the AP: 3,8,13,18,..... is 78?

$\bf{Solution}$

Given, AP is 3, 8, 13, 18, ...

Here, a = 3 and d = 8 – 3 = 5

Let nth term of given AP be 78. Then,

aₙ = 78 ⇒ a = ( n – 1 ) d = 78

⇒ 3 + ( n – 1)5 = 78

⇒     ( n – 1 ) 5 = 75 ⇒ n – 1 = 15 ⇒ n = 16

$\bf{Thus, 16th\ term\ is\ 78.}$