# URGENT HELP on fraction

• Jul 7th 2013, 11:45 AM
JojoZ
URGENT HELP on fraction
i need help with the following 2 fraction related questions:
1) determine whether the set of the following is closed for the given operation. Explain why, or why not. [what does it mean by closed?]
a) the set of positive fractions for subtraction.
b) the set of negative fractions for subtraction
c) the set of positive fractions for division
d) the set of positive fractions for multiplication

2) solve the following problem using strategy, or strategies, except algebra

Five jars contain a total of 92 chocolate bars. if each jars contains two more chocolate bars than the previous jar, how many chocolate bars are in each jar?(Hint: the bars can be split)
• Jul 7th 2013, 03:29 PM
DavidB
Re: URGENT HELP on fraction
Quote:

Originally Posted by JojoZ
. . .
2) solve the following problem using strategy, or strategies, except algebra

Five jars contain a total of 92 chocolate bars. if each jars contains two more chocolate bars than the previous jar, how many chocolate bars are in each jar?(Hint: the bars can be split)

You should be able to solve this problem using trial and error; it should take, maybe, three or four tries.

However, I am not clear about the problem:
If the bars can be split, can there be any left over?
Do the bars have to be split evenly (i.e. - in half only)?
• Jul 7th 2013, 06:49 PM
JojoZ
Re: URGENT HELP on fraction
ya, im not sure how many parts one chocolate bar can split into. And i was thinking when all the chocolate bars are split, it should have a total of chocolate bars.
• Jul 9th 2013, 06:36 AM
HallsofIvy
Re: URGENT HELP on fraction
This is a pretty basic algebra problem. Let "x" be the number of bars in the first jar. Then there are x+ 2 bars in the second jar, x+ 2+ 2= x+ 4 in the third jar, x+ 4+ 2= x+ 6 bars in the fourth jar, and x+ 6+ 2= x+ 8 bars in the fifth jar.

Add those, set the total equal to 92 and solve for x. The "bars can be split" is just to warn you that the solution may not be a whole number.
• Jul 9th 2013, 06:43 AM
Prove It
Re: URGENT HELP on fraction
Quote:

Originally Posted by JojoZ
i need help with the following 2 fraction related questions:
1) determine whether the set of the following is closed for the given operation. Explain why, or why not. [what does it mean by closed?]
a) the set of positive fractions for subtraction.
b) the set of negative fractions for subtraction
c) the set of positive fractions for division
d) the set of positive fractions for multiplication

2) solve the following problem using strategy, or strategies, except algebra

Five jars contain a total of 92 chocolate bars. if each jars contains two more chocolate bars than the previous jar, how many chocolate bars are in each jar?(Hint: the bars can be split)

For a set of numbers to be closed within an operation, it means that if you perform that operation on any numbers in your set, the result is ALWAYS a number in that set.