The colour code of a carbon resistor is, Brown, Black, Brown and Red. The value of the resistor is?

According to the colour code, brown colour stands for $1$, black for $0$ and red for  $2$.
First and second band represents the first and second significant number respectively.
So, it is  $10\Omega$.
Third band represents power of $10$ by which it is raised, so it is  $10^1$.
Last band represents the tolerance of resistor, so it is  $2$%.
Thus value of resistance,   $R=(10\times 10^1)\Omega \pm 2$% $=100\Omega \pm 2$%