1 In a class, there are 20 men and 15 women. Find the ratio of the number of men to the number of students in the class. First express the ratio as a fraction reduced to lowest terms. Then re write the ratio using a second method.

2.Determine whether each of the ordered pair is a solution of
3x-4y>7:

(0,0), (3,-6), (-2,-5),(-3,4)

3. A chemist needs to mix a 40% acid solution with a 70% acid solution to obtain the 12 litters of a 50% acid solution. How many liters of each of the acid solutions must be used? (2 points)

4. solve the portion: 45/2 = 360/x

5.graph each equation or inequality in the rectangular coordinate system. (4 points)
a.2x-y =4

b.3x-2y<-6

6 Solve each system by the graphing method. If there is no solution or an infinite number of solutions, state so.

a)2x-3y=12
-2x+y=-8

b)3x+2y=6
3x-2y=6

7. Solve each system by the substitution method. If there is no solution or an infinite number of solutions, state so.
a) 2x-y=6
x=13-2y

b) 3x+4y=-13
5y-x=-21

8.Solve each system by the addition method. If there is no solution or an infinite number of solutions, state so.

3x-4y=1
12x-y=-11

9. Health experts agree that cholesterol intake should be limited to 300 mg or less a day. Three ounces of shrimp and 2 ounces of scallops contain 156 mg of cholesterol. Five ounces of shrimp and 3 ounces of scallops contain 45 mg of cholesterol less than the suggested maximum daily intake (300 mg). Determine the cholesterol content of an ounce of each item.

I need to write 3 multi-step wordproblems with answers. One must use percentages, one must use exponents and the third can be any type. I have to include the process for solving each of the problems. The wordproblems don't have to be very difficult.

30. Assume that Joe take 6 hours working alone and Sam takes 8 hours working alone, how long does it take the, to do it together?
54. (1 +3i) (2-5i)
64. i(3-4i) (6+4i)
84. 14 + 5i divided by 3 +2i
94. 5 divided by 9i

Please see the attachment for proper formatting and symbols.
7.45 #5. Find a value, X0, such that µ = 160 and o2 = 256
a)P(X < X0) = 0.16
b) P(X-< X0) = 0.75
7.64 #16. A sample of size n = 20 is randomly selected from a normal population with mean µ = 90 and standard deviation = 5. Find the following:-
a. P (x > 95) t

A professor grades homework by randomly choosing 5 out of 12 homework problems to grade.
a) How many different groups of 5 are there from the 12 problems?
b) Jerry did only 5 problems of one assignment. What is the probability that the problems he did comprised the group that was selected to be graded?
c) Silvia did 7 pro

1. Wordproblems seem to daunt practically everyone. Discuss why they seem intimidating to you (or why not, if they don't). Do you believe that most of the problems we face in our daily life are wordproblems? Examples?
2. You are in the wonderful position of having to select a job from one of two offers you have just recei

Seven practiceproblems are in the attached file.
1. Use Cramer's rule to solve the system
x + y -z = -1
2x - 2y + 3z = -12
X + y - 4z = 13
Solution set is
2. Evaluate the determinate
5 0 0
1 -3 1
1 2 4
3. Use Cramer's rule to solve the system or to determine if it is inconsistent(I) or dependant(

Jack can shovel snow off the sidewalk in 3 hours. Joe can shovel snow off the same sidewalk in 2 hours. How long will it take them to shovel the sidewalk working together?

I am having difficulties with two practicewordproblems attached. Please help.
WordProblems:
1. The octane rating of a gasoline is a measure of the amount of isooctane in the gas. Subaru recommends 91-octane gasoline for the 2008 Legacy 3.0 R. How much 87-octane gas and 93-octane gas should Kelsey mix in order to make 12 g