What is the probability to reach the target if we enter randomly?

Hi all,
I'm trading by a lots of years with good and bad period.
I would like to ask to all people with more experience than me a simple maths concept.
Assuming we have random entry(buy or sell) and we only would like to target the 0.3% of our balance each trade.
What is the probability to reach the target if we enter randomly? what is the formula to calculate the probability?
After somebody gently answer this question i will continue the thread and explain the focus of my idea.
I want try to trade with the same banks concept.
Thank you in advance
bye

The probability is 50%. The Question is, what will you do if the market goes against you. Where will you stop, how long will you hold the trade (swap, margin call) and and and.... sounds a little bit like 1 pip profit and 1000 pips stop. 99,9% winning rate but this one loosing trade eat your profit.

best Regards