Answer:
Answer: 
 
The missing value is 1/60. 
 
Step-by-step explanation: 
 
Given, 
 
The time taken by Marie to work alone = 60 days, 
 
Since, 
 
 
 
Thus, the work done by Marie in one day = , 
 
Hence, the rate of Marie = 1/60 per day, 
 
Which is the missing value in the table. 
 
Explanation: