Question

1+3+5+7+9+11+13+15+17+19+21+23+25+27+29+31 calculate the number without adding actual number

Answer 1

This can be done using the formula,

$\boxed{ \bold{ s_{n} = \frac{n}{2} (first \: term \: + last \: term \: }}$




On applying formula,


$s_{16} = \frac{16}{2} (1 + 31) \\ \\ \\ \: \: \: \: \: \: = 8(32) \\ \\ \\ \: \: \: \: \: \: = 256$





$\bold{ \underline{Sum \: of \: given \: sequence \: is \: \: 256}}$

Answer 2

Your answer ⤵

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Sn = n / 2 ( a + an )

Sn = 16 / 2 ( 1 + 31 )

Sn = 8 ( 32 )

Sn = 256

Sum of these numbers is 256

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