
Step-by-step explanation:
Probability=
Probability for a randomly chosen girl to be senior=
Probability for a randomly chosen girl to be senior=
Probability for a randomly chosen boy to be senior=
Probability for a randomly chosen girl to be senior=
For two independent events,
Probability for both event 1 and event 2 to take place=
Since choosing boys and girls is independent,
Probability for both boy an girl chosen to be senior=
Probability for both boy and girl chosen to be senior=
So,required probability is 
Answer:
it's a star
Step-by-step explanation:
We have
3 / (x-5) - x/5
We make the GCF and we have
15/[ 5(x-5) ] - x(x-5)/[ 5(x-5)]
= [ 15 - x(x-5) ] [5(x-5)]
= [ 15 - x^2 + 5x] / [ 5 (x-5) ]
= [15 - x^2 + 5x]/[5x - 25]
An answer to your question is (15-x^2+5x)/(5x-25)
With amounts measured in gallons, let
x = amount of 65% antifreeze
y = amount of 90% antifreeze
1 gal of the 65% brand contains 0.65 gal of pure antifreeze; x gal would contain 0.65x gal. Similarly, y gal of the 90% brand contains 0.90y gal of pure antifreeze.
To obtain 120 gal of 80% antifreeze solution (which contains 0.80•120 = 96 gal of pure antifreeze), we must have
x + y = 120 … … … … … [total volume of antifreeze solution]
0.65x + 0.90y = 96 … [total volume of pure antifreeze]
Solve the first equation for y :
y = 120 - x
Substitute this into the second equation and solve for x :
0.65x + 0.90 (120 - x) = 96
0.65x + 108 - 0.90x = 96
0.25x = 12
x = 48
Solve for y :
y = 120 - 48
y = 72