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.
+118654 
