# Thread: I am in desperate need of help with various math problems.

1. ## I am in desperate need of help with various math problems.

Please Help me: I am taking Praxis II and I need some help with a few math problems (mid-level)?

I am sure that these are simple enough, but I want to make sure that I understand these. I took a practice test and I thought that I had done fairly well on it, but I missed 8 out of 30! I have a lot riding on this test, I have one chance to take it before the fall and if I do not pass, it will delay my graduation for one year. I feel really dumb, I have A's in all of my math classes, but this test seems to be hard for me. I will think that I have a grasp on it, but I have already failed it once. All help is appreciated and please make sure to explain your answer. Thank you!

1.) The population of country X is 0.36 billion persons, and the population of country Z is 12 million persons. The population of country X is how many times that of country Z?

2.) The 40 eggs in a box weight a total of x pounds. What is the average weight per egg for the eggs in the box, in ounces? a) x/640 b)56/x c)56x d)2x/5

3.) Shows a right triangle: side a=x side b=4 side c=w
What is x^2 in terms of w?

4.) Shows a graph with a line segment with the coordinates a(1,1) and b(4,4)
If line segment AB is flipped over the x-axis such that point A becomes point C and point B becomes point D. What are the coordinates for C and D?

4.) It shows three circles with one triable that goes through all three of them and they are arranged in such a way that the sides of the triangle makes up the radius of each circle. The problem reads:
Each circle is tangent to the other two circles. The points X, Y , and Z are the centers of the circles. If the circles have radii of 3, 4, and 5, respectively, what is the perimeter of triangle XYZ?

5.) P=XY
What would happen to the value of P in the equation above if the value of X was increased by 10% and the value of Y was decreased y 10%?

6.) A 4-inch by 6-inch photograph is to be enlarged by proportionally so that the 4-inch side expands to 5 inches. What would be the new length, in inches, of the 6-inch side of the photograph?

7.) A set consists of the letters A,B,C,D,E, and F. If order is not important, how many two-letter subsets are possible?

I know this is a lot of questions, but I really need help to make sure that I understand how to work them. I really do appreciate your time and help. Thank you in advance.

2. ## Re: I am in desperate need of help with various math problems.

Originally Posted by pjgirl
Please Help me: I am taking Praxis II and I need some help with a few math problems (mid-level)?

I am sure that these are simple enough, but I want to make sure that I understand these. I took a practice test and I thought that I had done fairly well on it, but I missed 8 out of 30! I have a lot riding on this test, I have one chance to take it before the fall and if I do not pass, it will delay my graduation for one year. I feel really dumb, I have A's in all of my math classes, but this test seems to be hard for me. I will think that I have a grasp on it, but I have already failed it once. All help is appreciated and please make sure to explain your answer. Thank you!
Since you didn't tell us where and what your difficulties are I can give you only hints what you should and can do.

1.) The population of country X is 0.36 billion persons, and the population of country Z is 12 million persons. The population of country X is how many times that of country Z?
Convert billions into millions and divide afterwards popX by popZ

2.) The 40 eggs in a box weight a total of x pounds. What is the average weight per egg for the eggs in the box, in ounces? a) x/640 b)56/x c)56x d)2x/5
Convert x pounds into ounces and divide this value by 40.

3.) Shows a right triangle: side a=x side b=4 side c=w
What is x^2 in terms of w?
Use the Pythagorean theorem. Make sure that you know which side of the triangle is the hypotenuse. (That's the longest side of a right triangle)

4.) Shows a graph with a line segment with the coordinates a(1,1) and b(4,4)
If line segment AB is flipped over the x-axis such that point A becomes point C and point B becomes point D. What are the coordinates for C and D?
Draw a sketch. Read the new coordinates from your drawing.

4.) It shows three circles with one triable that goes through all three of them and they are arranged in such a way that the sides of the triangle makes up the radius of each circle. The problem reads:
Each circle is tangent to the other two circles. The points X, Y , and Z are the centers of the circles. If the circles have radii of 3, 4, and 5, respectively, what is the perimeter of triangle XYZ?
Draw a sketch. You should notice that one side of the triangle is the sum of two of the three radii.

5.) P=XY
What would happen to the value of P in the equation above if the value of X was increased by 10% and the value of Y was decreased y 10%?
There are three possible cases: X > Y, X = Y, X < Y

Choose values for X and Y (for instance: X = 100, Y = 50; X = 100, Y = 100; X = 50, Y = 100), do the required calculations and see what happens to P.

6.) A 4-inch by 6-inch photograph is to be enlarged by proportionally so that the 4-inch side expands to 5 inches. What would be the new length, in inches, of the 6-inch side of the photograph?
Determine the $\displaystyle enlargement\ factor = \frac{\text{length of new side}}{\text{length of old side}}$

Use this factor on the 2nd side.

7.) A set consists of the letters A,B,C,D,E, and F. If order is not important, how many two-letter subsets are possible?
This question is unclear to me: Is AA a valid subset?

I know this is a lot of questions, <--- this is the gratest understatement of the whole thread
but I really need help to make sure that I understand how to work them. I really do appreciate your time and help. Thank you in advance.

3. ## Re: I am in desperate need of help with various math problems.

This has already been answered well but as an extra point:
For 1) make sure you take care in checking what your definition of billion is (i.e. 109 or 1012)
-jdbt