Expecting the i3 7100 to get 50-55H/s it would be 0.07$ in 24 hours. (power costs not included)
OK, but if we take electricity off and consider it also a work and also the CPU will die earlier and whole system will be slower then I am not sure where is the profit and why people do it?
Yes I was just saying that it is possible. Not that it would make any sense with a CPU like that.
On the other hand, If you got a rig with, for example, a threadripper 1950X CPU besides your GPUs it maybe would be more profitable.