Answer
The number is $5$.
Work Step by Step
Let
$x$ = the unknown number
Then
"a number increased by 5" means $x+5$
"two times a number" means $2x$
Thus, the equation that represents the situation is:
$x+5=2x$
Add $x$ on both sides of the equation to obtain:
$5=2x-x
\\5=x$