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A probability question 2015-08-19
From Omar:
Hi my name omar ,
I have an exam tomorrow and i want answer of this question
Thank you

Q:the probability distribution function of a discrete random variable X is given by
For X=0,1,2,3
a)the value of the constant k .

Answered by Penny Nom.
20 golfers playing four rounds 2015-08-17
From Paul:
I have a party of 20 golfers playing four rounds in fourballs. I realise that everyone will have 7 players that they do not play with, however I want to ensure that no one plays with the same person twice and that the Captain plays with the 12 players of his choice.
Answered by Victoria West.
Factor 2(x+1)(x-3)^2-3(x+1)^2(x-3) 2015-08-13
From Bella:
The directions are the solve and factor the expression completely: 2(x+1)(x-3)^2-3(x+1)^2(x-3)

I was factoring out an (x+1) and and (x-3) however the answer showing in my book is different and I can't figure out what I'm doing wrong please help

Answered by Penny Nom.
Parallelogram area 2015-08-04
From Nigel:
To find the area of a parallelogram you multiply the base by the height of the parallogram, the height being determined by an imaginary line drawn at right angles to the base. However if I made a parallelogram with joints at each corner and maipulated it to an upright position where the base and sides were at 90 degrees to each other,, I could then simply multiply the base times the height to get the area. Since the sloping side of the parallelogram does not vary in my imaginary jointed model, why can I not simply multiply the base by the sloping side to get the area in the same way that I multiply the base times the height of a square to find its area ? I cannot find the answer to this on the internet although I have searched.
Answered by Chris Fisher.
Rotating speakers through a 10 week schedule 2015-08-03
From Timothy:
I want 15 students to speak 7 times each over the course of 10 weeks.
They each will have 5 minutes.

Answered by Victoria West.
An oil field barrel 2015-08-02
From Michael:
I have a storage tank that is 12' diameter x 22.5' high
it's capacity is 450 oil field barrels (42 gallon)
Which would hold 19,036 us gallons
I'm trying to find out how many inches it would take to make 1 barrel
I was able to get this far by using your volume calculator, but haven't been able to come up with the rest!
Thank you very much for your time, and I really appreciate this site and the tools you all have made available to everyone for free!
Hope to hear back from you soon and God bless you all!!

Answered by Penny Nom.
The length of a shadow 2015-08-01
From maaz:
I am having trouble with this question:

Lizzie, who is 6 feet tall, stands in her driveway at night, exactly 24 feet from the base of a spotlight, and casts a shadow that is 12 feet long if her friend Hannah who is 5 feet tall decides to stand next to lizzie how long will her shadow be?

Answered by Penny Nom.
The distance between two boats 2015-07-26
From mohammad:
Two boats leave the same dock at the same time,one traveling due east at 10 mph and the other due north at 24mph,how many miles apart are the boats after 3hours ?
Answered by Penny Nom.
Scale 2015-07-24
From Kenneth:


Can you explain mathematically how the following scales become inches to feet?
For example, how does the scale of 1:160 become 1/16" = 1'?

(1:160) (1/16" = 1 foot) scale
(1:87) (1/8" = 1 foot) scale

I saw more of these different scale examples at the following:


I thank you for your reply!

Answered by Robert Dawson and Harley Weston.
Mary, Julie and Peter when on a trip 2015-07-10
From Edward:
How do you solve and set up a problem where: Mary pays one third of the cost of a trip, Julie paid half of what Mary paid, and Peter paid the remaining $75,
Answered by Penny Nom.
Golf for 12 with a proviso 2015-07-07
From Ken:
I hope you can help me. I'm trying to put together a draw for 12 players in 3 groups over 4 days. One proviso, 2 players must play together in each round because they require the use of a golf cart. We are due to play in September this year.
Thanking you in advance for any assistance you can give.

Answered by Victoria West.
The nth term 2015-07-04
From ujjal:
What is the nth term in the order 6,8,10....
Answered by Penny Nom.
Why is the area of square not conserved when it changes to a rhombus? 2015-06-28
From shubham:
Why is the area of square not conserved when it changes to a rhombus, both have equal sides still rhombus have less area than square.??
Answered by Penny Nom.
Why are bags of soil measured in litres? 2015-06-19
From Cheryl:
Why are bags of soil measured in litres?
Answered by Penny Nom.
My final exam score 2015-06-19
From Deirdre:
I got 69% on a question worth 20%
68% on a question worth 20%

And the final exam was worth 60%

My final grade overall was 63%

Did I do very bad in the exam????

Answered by Penny Nom.



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