Let's assume I play $10$ columns of a lottery, each costing $0.5 €$, i.e. in total $5 €$. From the lottery, I select $5$ numbers of $45$, plus $1$ number of $20$.
I continue to play in consecutive draws of the lottery. Let's assume I play three times a week, for $50$ weeks per year (i.e. $150$ times in total).
If the probability of getting $4$ numbers correct out of $45$ (and not getting the $1$ out of $20$ correct) is equal to $0,00081849\%$, is it right to assume that my probability of winning at least once is equal to $150 \times 0,00081849\% = 1,84\%$?
The answer is approximately $0.12267\%.$
It is much easier to calculate the probability you don't win, then subtract from $1$. The probability of you losing any given lottery is $100\%-0.00081849\% = 99.99918151\%$ which equals $0.9999918151.$ When this occurs $150$ times, you need to find $0.9999918151^{150}$ instead of $0.9999918151\cdot 150$, since we are dealing with probability and you have to multiply for each case.
$0.9999918151^{150} = 0.998773.$ Subtracting from $1$ gets about $0.0012267.$ In percentage that's $0.12267\%.$