Answer:
12¼ hours
Explanation:
The complete work will be 100% so the combination of efforts of Nancy and John would require more hours.
Given that the duration of 22¾ represent 65% then using the concept of cross multiplication, we first get the total number of hours required for the whole task.
If 65% represent 22¾ hours then what would 100% represent?
65%=22¾
100%=x
X=100*22¾ /65=35 hours
Remaining hours will be 35-22¾ = 12¼ hours
Therefore, additional 12¼ hours are needed by Nancy and John