Big Brother's Investment Deal

You may not even believe it if you tell me.An older brother said he is very optimistic about me.He is rich and willing to invest in meIt doesn't matter even if you lose everythingI plan to take 2000U and leave it here with me.Let me play and keep playingBut there are preconditionsIf you earn 2000U, you must return the principal to him as soon as possibleThen I earned another 2000U and I had to give it to him as soon as possible.For the money earned after that, 10% will be taken for every 2000UIn other words, the elder brother invested 2000UGet the principal back firstThen double itIn the end, for every 2000U he earned, he withdrew 10%Do you think I should promise my brother?In fact, the red envelope for the Chinese New YearPlus the 5,000 yuan withdrawnI can also take out 2000U myselfBut I don’t want to top up moneyso tangled