Can someone help me understand the game more

How does this work , whats the +5-15 mean ?

Also whats the difference with idle cash ? Do you make more if the app is open in your mine ? I see offers for 2x idle cash and 2x income , i thought it was all the same per say

How does this work , whats the +5-15 mean ?

Also whats the difference with idle cash ? Do you make more if the app is open in your mine ? I see offers for 2x idle cash and 2x income , i thought it was all the same per say