All Answers

+2354

Guest:
-4 1/3 + 3 3/4

look at the answer to this question,

it is very similar to your question and might give you a good hint

http://web2.0calc.com/questions/math_1506

reinout-gFeb 26, 2014

+2354

lilia123003:
how do i get x by itself when it is with sine

I think you mean something like sin (x) = 1/2,

then x = sin ^-1 1/2

This button is somewhere on your calculator, make sure you know whether you want degrees or radials.

If you don't know what i mean by that look at this;

http://www.mathwarehouse.com/trigonometry/radians/convert-degee-to-radians.php

This might also be useful to calculate some of the answers by heart

http://www.mathsisfun.com/geometry/unit-circle.html

reinout-gFeb 26, 2014

+2354

laserbeam808:
If one atom of uranium has the energy to make one granule of sand (1 mg) jump then how much mass would one anti-matter atom be able to lift? The energy for Uranium is 83140000/kg. The energy for Anti-matter is 180000000000/kg. Thanks!

You need to look at the ratio between the energy per kg for Uranium and Anti-matter.
The ratio is given by 180000000000/83140000= 2165.0229, multiply this by the 1mg of sand and you will find that an anti-matter atom can lift 2165.0229 mg.

Reinout

reinout-gFeb 26, 2014

+2354

catgirl:
what is two and eight elevenths divided by three and seven elevenths?

Remember that 1 = 11/11. Using that information we can rewrite 2 + 8/11 to 11/11 + 11/11 + 8/11 = 30/11

Doing the same for 3 + 7/11 = 11/11 + 11/11 + 11/11 + 7/11 = 40/11 we then have (30/11)/(40/11) = 30/40 = 3/4

reinout-gFeb 26, 2014

+118725

is there a question here?

MelodyFeb 26, 2014

#50

+118725

+14

*
Hello everyone,

Not all questions were answered today. I simply do not have time to answer every question when I am almost entirely on my own.
I made sure all member and regular helper questions were well answered. I think that I answered most of the others as well.
I left a few easier questions for other people to answer. I was pleased when I later saw that this had happened, for at least some of the questions.
The problem was that many of today's helpers seemed to be giving only the answer. The whole point of answering questions on any academic forum is to help people to learn.
In order to teach, you need to explain how you come by your answers. As I answer less questions, due to growing demand and time constraints, it is necessary for some of you to fill the void. If anyone would like to go back over today's questions and find any that need answering that would be appreciated. I know I can rely on you to help, both today and into the future.
Edit: Reinout has just been in and he says that they have all been answered now. Thank you so much Reinout-g.

Some people are already being a great help. Today, answers were given by Alan, king, fractionman, Red ranger, mathfreak and Queenblogger. I appologize if anyone was left out. Thank you everyone for your help.
I also had a really nice thank you from ihatetrig. We all like to be thanked for our efforts, I am no exception, I appreciate your show of gratitude.
A really interesting question was posted yesterday. Alan answered it and I added a little afterwards. Some of you may like to take a look. This is the web address.
http://web2.0calc.com/questions/coordinate-geometry. Highlight the address, right click and choose goto.
I will bump it up so that it stays visible for longer.

That is it for the evening,
Melody.

MelodyFeb 26, 2014

+118725

bump

MelodyFeb 26, 2014

#89

+118725

That is fabulous Reinout-g, I liked your explanation too.

NEW PUZZLE
Rules:
You have to use some or all of the numbers to make the magic number. You are not allowed to use any of the numbers twice. (Unless one was written twice in the first place)
You can use brackets, +, -, x, or divide and that is it.

EASIER ONE
9,3,7,1 and the magic number is 66

HARD ONE
2,3,8,7,25,100 And the magic number is 387

Happy Calculations

MelodyFeb 26, 2014

+118725

Guest:
Cody bought a jacket on sale for 50% off the original price, and another 25% off the discounted price. If the jacket originally cost $60.00, what was the final sale price for the jacket

50% of $60 = $30

100% - 25% = 75%

75% of $30 = 0.75 * 30 = $22.50

Or you could have found 25% of $30 = $7.50 This would be the second discount.

final amount would be $30.00 - $7.50 = $22.50

MelodyFeb 26, 2014

+118725

abdullah:
a cylinder whose height is two third of its diameter has the same volume as a sphere of radius 4cm.calculate the one third radius of the cylinder

Let the diameter of the cylinder be 2x cm (The radius is x cm) the height of the cylinder is (4x/3) cm

The volume of the Cylinder = pi * x ² * h ==> pi * x ² * 4x/3 ==> 4pi*x ³ / 3

The volume of the sphere = 4 * pi * r ³ ==> 4 ⁴ * pi ==> 256pi

4pi*x ³ / 3 = 256pi

x ³ / 3 = 64

x ³ = 192

x = 192 ^1/3

x = 5.769 cm ( to 5 decimal places)

I don't know why you would want 1/3 of the radius but it is 5.769/3 = 1.923cm

MelodyFeb 26, 2014

+118725

Guest:
Joan bought a jumper on February 21st on her credit card for $89.00. The rate of interest is 18% p.a. flat (i.e. 1.5% per month). How much does Joan owe after 2 months if she has not paid any amount off the card? There is no interest-free period.

I = Prt = 89 * 1.5/100 * 2 = $2.67

She will owe 89+2.67 = $91.67

MelodyFeb 26, 2014

+118725