David: We gotta split the bills guys
Monica: Sure, I'm looking at this email too
David: How bout you Nina?
Nina: I'm here, I'm here, 3 ways? 
David: I was gone for 2 weeks so maybe lets try to divide electricity different ways? 
Nina: Sure, any idea how to divide it?
David: I'll make some excel calculations
Monica: Just send it over, I'm fine with it
David, Monica and Nina will split the bills. David will divide the electricity bill differently, because he was gone for 2 weeks.