Question

which term of the A. P. 3,8,13,18........is78​

Answer 1

$\huge\star{\tt{\underline{\underline{\red{Answer}}}}}\star$

a=3

d=8-3

$\implies$5

$\bold{a}_{n}$=78

$\large{a}_{n}$=a+(n-1)d

By applying the formula

78=3+(n-1)5

78-3=(n-1)5

$\large\frac{75}{5}$=n-1

n=15+1

$\large{\boxed{\boxed{n=16}}}$

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Answer 2

$\huge\sf{Answer:-}$

a = 3

d = 8 - 3

So, 5

an = 78

an = a + ( n - 1 ) 5

Using Formula

= 78 = 3 + ( n - 1 ) 5

= 78 - 3 ( n - 1) 5

= 75 / 5 = ( n - 1)

= n = 15 + 1 = 16

Therefore, n = 16