Its funny, because today I saw a YT video where the guy stated that he explicitly did the math and was sure that spending 5 is the best.
But now I did the math myself and its true:
3>4>5
My approach:
5:
You spend 5x 0,2 in order to get 1
(1 x 1 + 0 * 0,2) /5 = 0,2
0,2 => 0,2
4:
You get
(0,8 x 1 + 0,2 * 0,2) /4 = 0,21
0,2 => 0,21
3:
You get
(0,6 x 1 + 0,4 * 0,2) /3 = 0,227
0,2 => 0,227
Therefor you have 13%(0,227/0,2) more output if you use 3 instead 5.