All i know that you lose 40% when you drop a tut,and lose less when you volley with that person and than drop.So i am only guessing that you need 1.6T to give a 280b profit
Well it usually takes around 3 times what you're dving. Of course I've never dv'd anyone that type of money so it may be more.
So around 1.4 tril if my math is correct but that's without dropping the tuts if you drop then just multiply it by .60 roughly
Multiply by 5? Ummmm no There is a difference, If you just want them to get to 280 bil, multiple their gain by 1.25. So, 350 bil, you will lose 350 bil. So, you'll need at least 350 plus 280 equals 630 bil at least. Recommended you have more. For any amount they make get to, multiple by 1.25 or (5/4), that is the amount you will lose. Add amount you lose with amount they gain and that should be a minimum you have. This is if no tutors are used repeatedly for volley.
I'm providing the case where you drop every tutor. Started typing right after you said multiply by 5. I tested this out many times with tutors, even did it last night. my calculations were dead on