Computer game log normally distributed

I'm playing a computer game and I want to boost the high score. I assume that attempts are independent (say, you do not improve by playing), and in each game my achieved points are lognormally distributed with mean 500 and variance 1’000’000. How often do I have to play so that your high score exceeds 1000 with probability at least 0.7 ?

My first guess would be to compute the value of a r.v. X which is my high score and set that P(x>1000)=1-P(x<=1000)= 1-0.7. But I don't know how to handle that information