Question

Fill in the blank with a number that follows the sequence :
, 39, 52, 65

Answer 1

Multiples of 13 are 13, 26, 39, 52, 65 and so on.

The numbers in the provided sequence are multiples of 13.

$39=13\times 3$
$52=13\times 4$
$65=13\times 5$

$\left[\right],39,52,65\to [\underset{–}{2}\times 13],\underset{–}{3}\times 13,\underset{–}{4}\times 13,\underset{–}{5}\times 13$

Hence, the first number should be $2\times 13=26$