 |
|
|
|
|
|
|
|
|
Some 5 card hands |
2002-03-28 |
|
From A student:
From a standard deck of cards how many 5 card hands are possible consisting of a. exactly 4 hearts
b. two cards of one kind and three of another(like a full house).
Answered by Penny Nom. |
|
|
|
|
|
|
100 from four 9's |
2002-03-27 |
|
From A student:
My teacher gave us a math problem to try and figure out and I am stumped. The problem was this.... by only using four nines, how can you get an answer of 100? You can add, subtract, multiply or divide...anything you need to do ,but you can only use four nines.
Answered by Leeanne Boehm. |
|
|
|
|
|
|
If the matrix A is inverible and AB =AC, then B = C |
2002-03-27 |
|
From Vikki:
i hope you can help i am soooo stuck here goes: a)
A= 0 1 B= 1 1 c= 2 5 0 2 3 4 3 4
A,B and c are matrices Evaluate AB and Ac (which I can do) then
b)
I need to prove that if the matrix A is inverible and AB =AC, then B = C. Why does this not contradict what happened in part a)?
Answered by Leeanne Boehm. |
|
|
|
|
|
|
Cube roots |
2002-03-26 |
|
From Kathy:
My son is in 4th grade and needs to simplify the cube roots of 216, 512 and 64. How does he do this with a regular calculator or without?
Answered by Penny Nom. |
|
|
|
|
|
|
A triangle in a circle of radius 6 |
2002-03-26 |
|
From Marko:
In a circle of radius 6, a triangle PQR is drawn having QR = 8 and PQ = 10. Determine the length of PR
Answered by Chris Fisher. |
|
|
|
|
|
|
A lottery question |
2002-03-25 |
|
From Noel:
I want to take all numbers in a Lotto game from 1 to 45 and ditribute them between 9 boxes each containing 5 numbers. Each number is used only once. - What is the probability that I derive the correct combination of 5 numbers in the draw?
- What is the probability if I take a systems game and now distribute 9 numbers into each of 5 boxes? Once again, the numbers are used only once.
- Can you explain what formulae are used and how the answer is derived? Is this a distribution or combination problem? Or is it a combination of both distribution and combination?
Answered by Andrei Volodin and Penny Nom. |
|
|
|
|
|
|
Unit fractions |
2002-03-23 |
|
From Laura:
Write 1/2 as the sum of ten different unit fractions.
Answered by Claude Tardif. |
|
|
|
|
|
|
A hamburger and a soft drink |
2002-03-23 |
|
From A student:
A GROUP OF FRIENDS WENT OUT TO LUNCH. EACH BROUGHT A HAMBURGER AND A SOFT DRINK. TOGETHER A HAMBURGER AND A SOFT DRINK COST MORE THAN A DOLLAR. THE TOTAL COST FOR THE GROUP WAS $17.81. THERE WAS NO TAX OR TIP INCLUDED. IF A HAMBUGER COSTS 2 CENT MORE THAN TWICE A SODA, FIND THE COST OF THE HAMBURGER.
Answered by Leeanne Boehm. |
|
|
|
|
|
|
A probability problem |
2002-03-23 |
|
From Kate:
If I have a spinner and then spinner has the numbers 1,2,3,4 on it and it is spun 3 times, what is the probability that the spinner will stop on 4,3,and 1 ? In that order?
Answered by Leeanne Boehm. |
|
|
|
|
|
|
A trigonometric identity |
2002-03-22 |
|
From Debby:
I am stuck on a problem and wondering if you can help?? It is: Prove the following:
sec2(X)+csc2(X) = sec2(X)csc2(X)
Answered by Harley Weston. |
|
|
|
|
|
|
Mr. Byrd's drive to work |
2002-03-22 |
|
From Mr. Bollen:
Mr. Byrd leaves his house at 7:00am to go to work. If he drives 40 mph he will arrive 3 minutes late and if he drives 60mph he arrives 3 minutes early. At what speed will Mr. Byrd have to drive in order arrive exactly on time. Please describe how you arrived at your answer.
Answered by Claude Tardif and Penny Nom. |
|
|
|
|
|
|
Range of values for standard deviation |
2002-03-22 |
|
From Susan:
What is the range of values for standard deviation? Is it between 0 and +3? Is it between +1 and +3?
Answered by Andrei Volodin. |
|
|
|
|
|
|
What fraction of the world's motor vehicles are built in Canada? |
2002-03-20 |
|
From A student:
About 1/4 of the world's motor vehicles is built in Canada or the United States. About 1/5 of the world's motor vehicles are built in the United States. What fraction of the world's motor vehicles are built in Canada?
Answered by Claude Tardif. |
|
|
|
|
|
|
Adding algebraic fractions |
2002-03-20 |
|
From Dolores:
I get totally confused with this problem. I get confused with the getting the lowest terms. 4/x-5 + -2/x -10/x^2-5x
Answered by Penny Nom. |
|
|
|
|
|
|
A cone in 3 space |
2002-03-20 |
|
From Matthew:
Let C in R3 be the cone defined by x2 + y2 - z2 = 0 (A) Let P be the plane described by x + 2z = 1 (i) Find a description of P in terms of two parameters s and t .
.
.
Answered by Walter Whiteley. |
|
|
