ElectricPavlov

30%  of  500 are French

.30 x 500 = 150 French

Where is the referred to figure ? 

Since everyone seems to be chiming in on this thought-provoking math problem, here is my take:

3/4   is   3 ÷ 24 = 0.125

813  is divisible by 3

813   would work

Find the distance from Robert (4,3) to EACH of the other points using the distance formula

distance =  sqrt ((x1-x2)^2 + (y1-y2)^2 )

let x1, y1   be Robert   (4,3)       and      x2, y2     be    Lucy  (6,1)

   then distance = sqrt (( 4-6)^2   +  (3-1)^2 ) =  

                             sqrt ( 4 + 4) = sqrt 8

    Now let x2 y2    be Liz ( 1,7)  

distance = sqrt ( ( 4-1)^2 + (3-7)^2 )

              = sqrt  (9 + 16)   = sqrt 25  

Now which is farther from Robert? 

I think you are saying the number of mosquitoes is given by   -x^2 + 14x     where x is the cm of rain?

max will be at   cm of rain = - b/2a     where b = 14   and   a = -1    

                                              - 14/ -2 = 7cm of rain will produce max mosquitoes

Need more info   but basically the pizza circumference would be     pi x d       where d = diameter of the pie  (round pie assumed)

x = faster tap

(x+20) = slower tap

1/x  + 1/(x+20) = 1/24

x + 20 + x = (x^2+20x)/24

48x + 480 = x^2 + 20x

x^2 -28x-480 = 0                        Use quadratic formula to find x = 40 min

Draw a Venn Diagram      12 students do not play those sports    15 students DO play those sports

15 out of 27       15/27