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
Table
<span> In favor Opposed Undecided
Grade 9 5 3 9
Grade 10 8 12 9
Grade 11 15 16 10
Grade 12 12 6 11
Probability = number of positive outcomes / number of possible outcomes
Probability that a student in grade 9 is in favor of extending the school day =
number of students in 9 grade in favor / number of students in grade 9
number of students in 9 grade in favor = 5
number of students in 9 grade = 5 + 3 + 9 = 17
Probability = 5 / 17
Answer: 5 / 17
</span>
Answer:
<h2>
$65</h2>
Step-by-step explanation:
Step one:
we are told that the ratio of Kailyn's money to Nathan's money is
4:9,
Nathan has $45, let Kailyn's money be x
therefore
4/9=x/45
cross multiply we have
9x=45*4
9x=180
divide both sides by 9
x=180/9
x=20
Kailyn's money is $20
Together they have =20+45= $65