Ron Need your help: usage of TIMES with and without as/than

[amir_hatef]

Hi Ron,
I have a big problem on understanding cases which we need to choose between usage of TIMES with AS/THAN and without AS/THAN:

1) The cost of a bag is $25, five times the cost ten years ago.
2) The woman is four times as old as her daughter.

As you see, in the first one, usage of times without AS/THAN and the second one is usage of times with as...as. I can NOT understand these question types, What is the general rule for such these staff?? How shall we know which one to use?? Another example of my doubt, same issue as above ones, is:
In the 1980's the rate of increase of the minority population of the united states was nearly twice as fast as the 1970's.
A.twice as fast as
B.twice as fast as it was in
C.twice what it was in
D.two times faster than that of
E.two times greater than
OA: C
Why B is wrong rather than C, while again, (B) uses TWICE with as...as BUT (C) ONLY uses TWICE without any as...as or than. What is the general rule to recognize this in SC gmat??
Also, about INCREASE and DOUBLE can you elaborate it by some good examples? Thanks a ton in advance Ron.

[amir_hatef]

Any Instructor!!! Ron, Stacey, Tim,... please come and help us. Thanks.

[RonPurewal]

Any Instructor!!! Ron, Stacey, Tim,... please come and help us. Thanks.

don't do this -- i.e., don't post a message that says "please answer my question".
this is called "bumping" the thread; it brings the thread up to the most recent position in the folder.

the problem, of course -- besides the obvious rudeness of this practice -- is that we answer the posts strictly in order from oldest to newest. therefore, if you post a message, with no content, that says "please answer this post", then you are moving the thread to the LAST place in the queue.

please be patient -- we will get to all of the threads. if you make posts like this one, you're just making it take longer.
thanks.

[RonPurewal]

this is not a grammar issue; it's a meaning issue.

if you are directly comparing numerical quantities, then you just say "QUANTITY1 is N times QUANTITY2".
note your examples:

1) The cost of a bag is $25, five times the cost ten years ago.
2) In the 1980's the rate of increase of the minority population of the united states was nearly twice what it was in the 1970's.

note that "cost" and "rate of increase" are NUMERICAL QUANTITIES. therefore, they can be directly compared.

--

if you are comparing things or people according to some quality, then you have to use "as ADJ as" or "as ADV as" accordingly.

2) The woman is four times as old as her daughter.

the woman and her daughter are not numerical quantities, so a direct comparison (like the ones above) would be total nonsense.

Why B is wrong rather than C, while again, (B) uses TWICE with as...as BUT (C) ONLY uses TWICE without any as...as or than. What is the general rule to recognize this in SC gmat??

the combination of "rate" and "fast" is incorrect.
see here:
post44894.html#p44894

Also, about INCREASE and DOUBLE can you elaborate it by some good examples? Thanks a ton in advance Ron.

you've got to make this question more specific -- do you have examples in mind? specific problems in which you've seen these things?

[amir_hatef]

Thanks Ron for your NICE AWESOME explanation, I got all referring to the post you had written earlier,EXCEPT still I have a doubt as follows:

Q.The number of people flying first class on domestic flights rose sharply in 1990, doubling the increase of the previous year.

A)doubling the increase of
B)doubling that of the increase in
C)double as much as the increase of
D)twice as many as the increase in
E)twice as many as the increase of
OA: B
Here, although, this question has been discussed many many times at different places, but really I still have issue on below concepts tested:
1)can you breakdown the sentence skeleton for me and POE in terms of comparison concept, more specifically ''twice vs. double'' usage on GMAT? How can we reach to B??
2)What is the difference in usage on GMAT between ''increase in'' vs. ''increase of''??
3)Is the sentence tries to compare ''The number of people flying first class on domestic flights in 1990'' with ''The number of people flying first class on domestic flights previous year''??? Did i get the comparison elements correctly??
4)Choice (B), though it is the answer, I have issue on comparisons problems using ''that of'' or ''those of''? Can you bit explain it??

Again, thanks so much in advance and appreciate all your help during my prep.

[tim]

something doesn't seem right about the example sentence you provide, which will make it difficult to answer your questions. can you provide a source for the problem so we can verify that you have copied it correctly?

[amir_hatef]

can you provide a source for the problem so we can verify that you have copied it correctly?

SOURCE is: GMATPrep SC part, Official GMAC Software.

Ron, Stacey, Can you PLEASE and PLEASE clarify my doubts on this regard??? Thanks.

[RonPurewal]

can you provide a source for the problem so we can verify that you have copied it correctly?

SOURCE is: GMATPrep SC part, Official GMAC Software.

Ron, Stacey, Can you PLEASE and PLEASE clarify my doubts on this regard??? Thanks.

if you really got this problem in GMATPrep, and not from a third-hand source, then check again -- the answer is definitely not (b).
(this may ease your mind -- the pronoun "that" in that choice is wrong; it doesn't refer to anything at all.)

then, after you check your source, please post on this existing thread, which is in the correct folder:
the-number-of-people-flying-first-t5600.html

this, here, is the GENERAL VERBAL folder; do *not* post gmat prep questions in this folder. thanks.