It is between 3.1 and 3.17 or 3.2 if you want it by hundredths.
This is because 3.16 is 3.1600000 and many more zeros but 3.16227766 is slightly over that so it would be between 3.1 and 3.17.
 
        
                    
             
        
        
        
Answer:
4 brothers and 3 sisters
Step-by-step explanation:
Let x be the number of brothers and y be the number of sisters in the family.
1.  Each brother has x-1 brothers and y sisters. If each brother has as many sisters as brothers, then

2. Each sister has y-1 sisters and x brothers. If each sister has twice as many brothers as she has sisters, then

3. Solve the system of two equations:

Then 

 
        
             
        
        
        
Let
x----------> number of weeks
y----------> saved money
we now that
<span>Michael begins with $20 and saves $5 per week
so
y=20+5x------> equation 1
and
</span><span>Lindsey begins with no money, but saves $10 per week
</span><span>y=10x-------> equation 2
</span><span>the number of weeks it will take for Lindsey and Michael to save the same amount of money is when equation 1 is equals to equation 2
</span>
therefore
20+5x=10x------> 10x-5x=20------> 5x=20-----> x=20/5-----> x=4 weeks
the answer is 
4 weeks
        
             
        
        
        
1. 700 calories
2. Half a serving
3.x=serving
350x=calories