Question

Which term of A.P. 3 , 8 , 13 , 18 .......is 78​

Answer 1

$\huge{\mathcal{\blue{\underline{Answer}}}}$

first term = 3

Common difference = 8-3= 5

$an = a + (n - 1)d \\ 78 = 3 + (n - 1)5 \\ 78 - 3 = (n - 1)5 \\ 75 = (n - 1) 5 \\ \frac{75}{5} = n - 1 \\ 15 = n - 1 \\ 15 + 1 = n$

$\huge{\mathcal{\blue{\underline{n=16}}}}$

☑ The 16th term is 78

Answer 2

Answer:

16

Step-by-step explanation:

let the last term of ap is an