Question

Find out the wrong number in the series. 3, 7, 15, 27, 63, 127, 255

Answer 1

The wrong number is 7 as all others are divisible by 3..

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Answer 2

Answer:

27

Step-by-step explanation:

The given series is

3, 7, 15, 27, 63, 127, 255

We need to find the incorrect number in the given number series.

$3+4=3+4=7$                  (Add 4)

$7+4\times 2=7+8=15$                (Add twice of 4, i.e., 8)

$15+8\times 2=15+16=31$            (Add twice of 8, i.e., 16)

$31+16\times 2=31+32=63$               (Add twice of 16, i.e., 32)

$63+32\times 2=63+64=127$                (Add twice of 32, i.e., 64)

$127+64\times 2=127+128=255$             (Add twice of 64, i.e., 128)

All numbers of the given series are correct except 27.

Therefore, 27 is the wrong number in the given series.