Your answer for the girls in the gymnastics club is correct.
Do the percentage of water the same way:  Divide 139 by 197.
That'll give you the decimal amount that's covered by water.
To change the decimal to a percentage, move the decimal point 
two places that way  ==> .
        
             
        
        
        
Answer:

Step-by-step explanation:
The picture of the question in the attached figure
step 1
we know that
 ----> by complete circle
 ----> by complete circle
substitute the given values

solve for x

step 2
Find the measure of arc JM

substitute the value of x

 
        
                    
             
        
        
        
First find how much she makes per day for the 16 pages. Then divide it by the amount of hours she works to find her hourly average. So I guess you can use all these proportions. 
 
        
                    
             
        
        
        
To find Kevin's age, subtract 17 by 3 to find how old Kevin is, which is 7. Then, to find Uncle rob's age, add 17 plus 3 to get 20, then multiply that by 3 to see how old Uncle Rob will be, which is 60.Then, subtract 6 from 60 to get 54.The final answer is that Kevin is 7 years old, and Uncle Rob is 54 years old. Hope this helps!