Question

if 3,8,13-----243 is an A.P then find its 18th term​

Answer 1

Answer:

a = 3

d  5

so,

18th term = a+ 17d

3 + 17(5)

78

THEREFORE 18TH TERM IS - 78

Answer 2

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$\mathtt{\huge{\underline{\red{Answer\: :}}}}$

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$\: \: \implies \displaystyle \sf \: tn = a + (n - 1)d$

$\: \: \implies \displaystyle \sf \: t18= 3 + (18 - 1)5$

$\: \implies \displaystyle \sf \: t18 = 3 + 17 \times 5$

$\: \implies \displaystyle \sf \: t18 = 3 + 85$

$\: \implies \displaystyle \sf \: t18 = 88$