If 40% are boy and there are 12 boys
40% of girls would be 12 and another 20% is 6 so 
You add 12+12+6=30 students total
        
             
        
        
        
Answer:
y=45+x
y=2x+15
x=30
Step-by-step explanation:
 
        
             
        
        
        
If you're rolling a single cube, then ...
-- There are 6 possible out comes.
-- One of them (5) is a multiple of 5 .
-- The probability of rolling it is (1/6) = <em>16-2/3 %</em> .
If everything is acting perfectly random, then ion 100 rolls, 
you'd expect to succeed 16 or 17 times.
If you're rolling a pair of cubes, then ...
-- There are (6 x 6) = 36 possible outcomes.
-- There are seven ways to get a multiple of 5.
(1+4),  (4+1),  (2+3),  (3+2),  (4+6),  (6+4),  (5+5)
-- The probability of rolling one of those is
                                                             (7/36) = <em>19-4/9 %</em> .
If everything is acting perfectly random, then in 100 rolls, 
you'd expect to succeed 19 or 20 times.
        
             
        
        
        
B. The product of two irrational numbers if rational
Example: The square root of 2 times the square root of 3, is the square root of 6, which is still irrational. 
        
             
        
        
        
9514 1404 393
Answer:
   see attached
Step-by-step explanation:
I like to use a spreadsheet for repetitive calculations. The distances are computed from the distance formula:
   d = √((x2 -x1)^2 +(y2 -y1)^2)
The results are shown in the second attachment. The drawing in the first attachment has the lengths rounded to the nearest tenth.