What if i give you one cent and will double whole month with how much u will end up?

You mean that you get 1c on the first day,2c on the second day,4c on the 3rd day,...... for 30days?

This is the sum of a GP    a=1, r=2, n=30

$$\\\boxed{S_n=\frac{a(r^n-1)}{r-1}}\\\\
S_{30}=\frac{1(2^{30}-1)}{2-1}\\\\
S_{30}=(2^{30}-1)$$

$${{\mathtt{2}}}^{{\mathtt{30}}}{\mathtt{\,-\,}}{\mathtt{1}} = {\mathtt{1\,073\,741\,823}}$$  cents

$10,737,418.23     Not bad for a months pocket money  

with one million