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A conditional probability problem |
2015-08-24 |
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From Faustina.:
Please I have an exam tomorrow. And I have tried by best in solving this Question. An urn contains 10 white, 5 yellow and 10 black marble. A marble is chosen at random from the urn and it is noted that it is one of the black marble, what is the probability that it is yellow?
Answered by Penny Nom. |
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Four equations in 3 unknowns |
2015-08-23 |
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From damien:
solve:
S x U - T = 44
T - U x S = 36
U + T - S = 7
U x U / S = 4
Answered by Penny Nom. |
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Reinforced steel mesh in a circular foundation |
2015-08-22 |
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From Padmesh:
in a circular foundation we are laying a reinforced steel mesh . i.e., like chords in both ways. the circle diameter is 2.91m and rods are placed 0.1m spacing. so I want to find the number of rods present in that circle. here by I am attaching an auto cad drawing for your reference
Answered by Penny Nom. |
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Arrangements of the letters STRANGE |
2015-08-22 |
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From Ravi:
In how many ways can the letters of the word STRANGE be arranged to that the vowels occupy only the old places.
Answered by Penny Nom. |
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A two digit number |
2015-08-21 |
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From Cameron:
Write the 2 digit number that matches the clues.
My number has a tens digit that is 8 more than the ones digit. Zero is not one of my digits.
My number is ________.
Answered by Penny Nom. |
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The distance over a Quonset |
2015-08-20 |
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From jane:
total base of hemisphere is 30 ft
apex height is 20 feet
what is total length over dome
Answered by Penny Nom. |
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A probability question |
2015-08-19 |
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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
P(X=x)=kx^3
For X=0,1,2,3
a)the value of the constant k .
Answered by Penny Nom. |
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20 golfers playing four rounds |
2015-08-17 |
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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. |
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Factor 2(x+1)(x-3)^2-3(x+1)^2(x-3) |
2015-08-13 |
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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. |
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Parallelogram area |
2015-08-04 |
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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. |
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Rotating speakers through a 10 week schedule |
2015-08-03 |
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From Timothy:
I want 15 students to speak 7 times each over the course of 10 weeks.
They each will have 5 minutes.
Thanks
Answered by Victoria West. |
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An oil field barrel |
2015-08-02 |
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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. |
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The length of a shadow |
2015-08-01 |
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From maaz:
Hello
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. |
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The distance between two boats |
2015-07-26 |
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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. |
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Scale |
2015-07-24 |
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From Kenneth:
Hello:
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:
http://www.oakridgehobbies.com/hobby-shop/modeling-in-scale-dimensions-f-a-q-s.html
I thank you for your reply!
Answered by Robert Dawson and Harley Weston. |
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