i will take your 10 btc and will make 20 bitcoins

of course I will save some bitcoin as a backup when there is something undesirable. then a couple of other bitcoin will I use to invest or set up a business, the most likely course I'll use in trading cryptocurrency

How you are going to do that? Don't say that you are going to invest that into those hyip scams and going to make that double easier? I'm sorry if I am thinking that way.

But you must be specific on how you are going to make that 10 bitcoins into 20 bitcoins and if you have legit way then why not share it here.

So that we are all going be happy with your strategy.

if you really gave 10 bitcoin to me, then I will use some of the bitcoin to invest (bitcoin altcoin trading and mining bitcoin), and the other I hold and sell at the right time

Hehe but the big question will be how you gonna manage to almost double that 10 bitcoin. 
I think there is no way to just double our bitcoins other than gambling but risk of lossing all 10 in one click is also high with gambling.

I would do about the same I love to example every now and then so I would also use a small fixed percentage to gamble and try my luck the rest I would invest with and trade with and a small part I'd let it on my wallet just incase I'd lose the rest haha.

I have not seen these people who are just willing to give money to an empty gambling. It's a black hole that will swallow all your money. Could not find a suitable attachment or complication of their funds.

I would rather cash out that 5% better than gambling it atleast, as i'm not a lover of gambling though i used to play sometimes just for fun with just small deposits that i never cared losing about.

If I get 10 BTC as a single batch I would immediately move 8 or 9 BTC's to a cold wallet and keep it in a secure place hard for me to reach, Then use the remaining 1 BTC as an investment and spend some of it in every interesting investment I find around.

i will hold that 10 bitcoin for high price and i think its a best way to hold your bitcoin for the present time because bitcoin will be increasing its price too much in the near future and i am sure we can get a huge profit from bitcoin in the near future.