I think its total of the two companies cash flows plus the synergetic benefit of 10 p.a less the gain of 4 by Nairobi shareholders
For example in yr 1: Nairobi Cashflow 20 + Delhi CF 8 + Syng Benft 10 = total of 38 less gain of 4 = 34. However there is need to clearly understand whats going on here. Somebody may clarify it better.