When you multiply 35 x 40 = 1400
:)
        
             
        
        
        
The ratio of yellow balloons to blue balloons is 8:12
Then there are 100 balloons. Making the equation, we are able to have:
8X + 12X = 1000
20x = 1000
X = 50.
Yellow balloons = 8x = 8 * 50 = 400 yellow balloons
Blue balloons = 12X = 12 * 50 = 600 blue balloons
So there are  400 yellows balloons.
        
             
        
        
        
Yes. 
1 inch = 2.54 centimeters, for example. These two dimensions are the same, but the units are different.
 
        
             
        
        
        
To get the correct angle where the arcs meet : it's more precise
        
             
        
        
        
Translate into Alg 15h - 25