You are correct, only C & E are close. But, IMO, C wins over E.
The comparision in E is not correct.
E:...four times as many as four years ago.: four times as many as what? four years ago?
C:... four times as many as there were (microcomputers for every....) four years ago.

IMO C

"as many as there were"

OA is C.

Actually my confusion is :

OA is saying that in E, the phrase 'four times as many as' is modifying 'pupil' -> so incorrect
While in C, the phrase 'four times as many as' is modifying to 'there are...' -> so correct

I want to understand, is there any general rule for this ?

e.g. a prepositional phrase can modify to previous clause.

here 'four times as many as' : what type of phrase it is ?

C is correct here and keeps the intended meaning as it is.

E changes the meaning of the sentence.

original sentence has meaning as 'only one computer for 32 pupils'

E says that every 32 pupils has one computer, means there are in total 32 computers. This is wrong meaning.

paes wrote:A recent national study of the public schools shows that there are now one microcomputer for every thirty-two pupils, four times as many than there were four years ago

(A) there are now one microcomputer for every thirty-two pupils, four times as many than there were
(B) there is now one microcomputer for every thirty-two pupils, four times as many than there were
(C) there is now one microcomputer for every thirty-two pupils, four times as many as there were
(D) every thirty-two pupils now have one microcomputer, four times as many than there were
(E) every thirty-two pupils now has one microcomputer, four times as many as

[spoiler]OA Later.
Please explain C and E.[/spoiler]

paes wrote:A recent national study of the public schools shows that there are now one microcomputer for every thirty-two pupils, four times as many than there were four years ago

(A) there are now one microcomputer for every thirty-two pupils, four times as many than there were
(B) there is now one microcomputer for every thirty-two pupils, four times as many than there were
(C) there is now one microcomputer for every thirty-two pupils, four times as many as there were
(D) every thirty-two pupils now have one microcomputer, four times as many than there were
(E) every thirty-two pupils now has one microcomputer, four times as many as

[spoiler]OA Later.
Please explain C and E.[/spoiler]

Have some examples:

I have 20 books, 4 times as many as (I have) one year ago.

=> I have 20 books, 4 times as many as one year ago.

One thing:

"As + Clause" is the acceptable form in GMAT. When we use "AS", we need to have a clause after it. If it is not there, we can assume that something is silent there.

They have 100 cameras now, 10 times as many as they were one year ago.

=> They refers to what?

=> They cannot refer to cameras for the following reason-
1. They is the subject in its clause, but cameras is the object in its clause. They are not parallel.

Conclusion:

In the option E,

every thirty-two pupils now has one microcomputer, four times as many as (they were) four years ago.

=> They refers to pupils. It does not make sense. So, E is out.

Answer is C.

c
comparison is between the number of computers..not computer per pupil.

gmat_perfect wrote:

paes wrote:A recent national study of the public schools shows that there are now one microcomputer for every thirty-two pupils, four times as many than there were four years ago

(A) there are now one microcomputer for every thirty-two pupils, four times as many than there were
(B) there is now one microcomputer for every thirty-two pupils, four times as many than there were
(C) there is now one microcomputer for every thirty-two pupils, four times as many as there were
(D) every thirty-two pupils now have one microcomputer, four times as many than there were
(E) every thirty-two pupils now has one microcomputer, four times as many as

[spoiler]OA Later.
Please explain C and E.[/spoiler]

Have some examples:

I have 20 books, 4 times as many as (I have) one year ago.

=> I have 20 books, 4 times as many as one year ago.

One thing:

"As + Clause" is the acceptable form in GMAT. When we use "AS", we need to have a clause after it. If it is not there, we can assume that something is silent there.

They have 100 cameras now, 10 times as many as they were one year ago.

=> They refers to what?

=> They cannot refer to cameras for the following reason-
1. They is the subject in its clause, but cameras is the object in its clause. They are not parallel.

Conclusion:

In the option E,

every thirty-two pupils now has one microcomputer, four times as many as (they were) four years ago.

=> They refers to pupils. It does not make sense. So, E is out.

Answer is C.

They have 100 cameras now, 10 times as many as [] one year ago.
why are you completing the sentence with 'they were' ?
If we complete it by
They have 100 cameras now, 10 times as many as they had one year ago.
then it will make sense.

Yes, you are correct. It should be "i had" in the first example, but in the second example "they were" is right. I have meant "they were" the cameras were. Since cameras is not the subject of its clause, they can not logically refer to cameras. It was my intent.

Thanks.

C look sperfect.

I have a query here. In "four times as many as there were.. "
Is "four times" adjective or noun?

kvcpk wrote:C look sperfect.

I have a query here. In "four times as many as there were.. "
Is "four times" adjective or noun?

four times acts as a adverb...telling you more informatin about HOW MANY MORE supercomputers there are right now compared to a moment in the past....

words that give you more information about why, when, how, where act as adverb...

adi_800 wrote:

kvcpk wrote:C look sperfect.

I have a query here. In "four times as many as there were.. "
Is "four times" adjective or noun?

four times acts as a adverb...telling you more informatin about HOW MANY MORE supercomputers there are right now compared to a moment in the past....

words that give you more information about why, when, how, where act as adverb...

Thanks Adi..