सदस्य: Melody

jyotig:
At the fair, 220 balloons are given to 40 children, 3/8 of whom are girls. Each boy receives the same number of balloons. Each girl receives twice as many balloons as each boy. How many more balloons do all the girls receive than all the boys?
Changes have been made in red.
Need MEthod, No Algebra!

40 children
3/8 of 40 = 15 girls therefore 25 boys

boys get some multiple of 25 balloons, girls get the same multiple of 30 balloons.
so
Some number times(30+25) = 220 balloons
Some number times 55 = 220 balloons
4 * 55 = 220
so the number is 4
The boys get 25*4 = 100 balloons
the girls get 30*4 = 120 balloons

You tell me, how many more balloons do the girls get.

Maybe you could have done this one yourself ? It was much easiler than the other ones.

Melody19 Feb 2014

+118692

jyotig:
Class A folds 160 fewer paper cranes than class B and 2/3 as many paper cranes as Class C. Class B folds 92 more paper cranes than class C. How many cranes does class B fold?

Need a method, not an answer. No Algebra!

Well JyotiG

If you are going to keep asking questions like this you simply have to learn some algebra.
I will talk you through it. If you don't understand say so. Are you prepared to give it a go?
*Added after I finished:This question is particularly difficult for you. If you want to learn to do these you probably should start with easier ones.
By the way, that question that I answered for you, where i kept referring to mum's and dad's, that was algebra. The only little difference was that with real algebra I would have replaced mum's with M and dad's with D. If you understood that, then you can understand algebra!

I am going to call the number of cranes that class A makes 'cranesA' normally i would just call it A but I am trying to ease you into algebra.
The number of cranes that class B makes can be 'cranesB'
and the number of cranes that class C makes can be 'cranesC'

Now i have to change the words into equations. This is how it is done.

Class A folds 160 fewer paper cranes than class B
cranesA = cranesB - 160

Class A folds 2/3 as many paper cranes as Class C.
cranesA = 2/3 of C (of is multiply)

Class B folds 92 more paper cranes than class C.
CranesB = cranesC + 92

How many cranes does class B fold?

These are the equations that I now have
cranesA = cranesB - 160..... (1)
cranesA = 2/3 * cranesC..................(2)
CranesB = cranesC + 92.......(3)

equation 1 and 3 both have cranesB in them.
I am going to replace cranesB in the first one with cranesC+92 from the third one.
cranesA = cranesC +92 -160
cranesA = cranesC -68 ........(4)
Now I am going to put (4) into (2) like this
cranesC - 68 = 2/3*cranesC
If I subtract 2/3 of the cranes class C made from both sides I get
1/3 of cranesC - 68 = 0
If I add 68 to both sides I get
1/3 of cranesC = 68
multiply both sides by 3 and I get
3 * 1/3 of cranesC = 3*68
cranesC = 204

Now we have
cranesC = 204 and
cranesA = 2/3 * cranesC..................(2) so
cranesA = 2/3 * 204 = 136

and now we have
cranesC = 204 and cranesA = 136 and cranesB = cranesC + 92.......(3) so
cranesB = 204 + 92 = 296

My answer is: Class A makes 136, classB makes 296 and class C makes 204
CHECK:
Class A folds 160 fewer paper cranes than class B (296-136=160 check) and 2/3 as many paper cranes as Class C. (2/3 of 204=136 check)
Class B folds 92 more paper cranes than class C. (204+92=296 check)
Good, everything is correct.

Now Jyoti, this was a difficult question that many 15 year olds would not be able to do. If you can't understand what i have done do not be too disheartened. You really need to start with easier questions.
If you would like me to get you started with algebra you only have to ask.
But please join up.

Melody19 Feb 2014

+118692

Guest:
Hi, Thanks for your reply. Sorry for the rudeness in my few posts.So, what I understood was that you're saying my first step is correct. Then, you said to divide 156 by 2/5 which equals 156/1 * 5/2. I got 390 marbles for Daniel. Is my math correct?

Thanks Again,
JyotiG

Well, have you put your answer into the original question to see if it works? Do you understand what I mean?
On a question like this you should be able to see for yourself it is correct.

Melody19 Feb 2014

+118692

stupid thing:
:o w*f is wrong with this calculator inverse of cos is WRONG ALL THE THINGS I HAVE PUT IN ARE VALID NOT INVALID PEICE OF $%#@&!!!!

There have been some recent upgrades so maybe you have found a bug, but i just checked one inverse cos and it worked fine.
What calculation were you trying to do. I would like to see for myself.
Thank you
Melody.

Melody19 Feb 2014

+118692

do you mean the web2.0calc ?

There is no fraction button. If you want to input 3 and 5/6 you are best to put it in as (3+5/6) The brackets will make it just one number. If this is part of a bigger question,the brackets will stop errors from happening.

Melody19 Feb 2014

+118692

jyotig:
Here's the question:
Daniel and William have some marbles. Daniel find that 2/5 of the number of marbles he has is 4/5 the number of marbles William has. William has 195 marbles. How many marbles does Daniel have?
I did 4/5*195 and got 156 as my final answer. Is it correct or is there an extra step?

No Algebra!