Question

15,18,32,101,405,1997,11974
Find the wrong number

Answer 1

Answer:

405 is wrong number...

Answer 2

Hence, the wrong number is "405(correct, 398)".

Step-by-step explanation:

The given sequence are:

15, 18, 32, 101, 405, 1997, 11974

To find, the wrong number = ?

The pattern follow:

$\times 1 +3,\times 2 -4, \times 3 +5, \times 4-6, .... .$

$18=15\times 1+3=15+3=18$

$32=18\times 2-4=36-4=32$

$101=32\times 3+5=95+5=101$

$405=101\times 4-6=404-6=398\neq 405$

$1997=398\times 5+7=1990+7=1997$

$11974=1997\times 6-8=11982-8=11974$

The wrong number is 405(correct, 398).

Hence, the wrong number is "405(correct, 398)".