Answer:
41.5 units
Explanation:
Given the data :
Month : J F M A M J J A S O N D
Inflow : 3 4 5 3 4 10 28 17 7 6 3 2
Outflow : 7 8 7 11 6 8 21 12 5 4 5 9
The unit of water in reservoir at the middle of August :
Initial unit = Unit of water at the start of the year = 50
Middle of August :
Inflow = 17 /2 = 8.5
Outflow = 12 /2 = 6
Unit of water at the middle of August :
Initial unit + Inflow - Outflow
Inflow till mid-August = (3+4+5+3+4+10+28+8.5) = 65.5
Outflow till mid-August = (7+8+7+11+6+8+21+6) = 74
50 + 65.5 - 74 = 41.5