neokeynesian

10-31-2004, 04:34 AM

1) What is the value of x if x/2=n!

a)??

b)360

c)??

d)520

e)1440

a)??

b)360

c)??

d)520

e)1440

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neokeynesian

10-31-2004, 04:34 AM

1) What is the value of x if x/2=n!

a)??

b)360

c)??

d)520

e)1440

a)??

b)360

c)??

d)520

e)1440

saurabhmalpani

10-31-2004, 05:19 AM

E is the Ans ..

2*7!= 1440

Saurabh Malpani

2*7!= 1440

Saurabh Malpani

neokeynesian

10-31-2004, 05:35 AM

Can u explain how u got it

Thanks

Thanks

vn_snoopy

10-31-2004, 07:51 AM

E is the ans since 2*6! = 1440. But I just simply do the computation.

lorcar

10-31-2004, 05:14 PM

how to do such a calculation in ONE MINUTE???

actually this is my only problem...i do not find the question difficul, but the timeeeeeeeeeeeeeeeeeeeeeeeeeee

actually this is my only problem...i do not find the question difficul, but the timeeeeeeeeeeeeeeeeeeeeeeeeeee

neokeynesian

11-01-2004, 05:07 AM

Yes, i also having the same problem as lorcar!

lmtuan

11-01-2004, 12:50 PM

1! = 1

2! = 2

3! = 6

4! = 24

5! = 120

6! = 720

7! = 5040

From answer choices, we can guest x=1440. :)

2! = 2

3! = 6

4! = 24

5! = 120

6! = 720

7! = 5040

From answer choices, we can guest x=1440. :)

vn_snoopy

11-02-2004, 03:52 PM

one of my friend told that, since this is not a large number, we can remember it. And I have to admit that he has very good memory.

bscout

11-23-2006, 11:34 PM

Anyone can explain this question?

TargetGRE6

11-24-2006, 02:39 AM

Anyone can explain this question?

Very simple, if we use reverse substitution.

Factorial of a number is 1*2*3*4*...*n.

Hence possible factorials are :

1! = 1

2! = 2

3! = 6

4! = 24

5! = 120

6! = 720

7! = 5040

Now x = 2*n! If we look for all the options, only 1440 makes sense.

Very simple, if we use reverse substitution.

Factorial of a number is 1*2*3*4*...*n.

Hence possible factorials are :

1! = 1

2! = 2

3! = 6

4! = 24

5! = 120

6! = 720

7! = 5040

Now x = 2*n! If we look for all the options, only 1440 makes sense.

bscout

11-24-2006, 12:24 PM

Got it. Thanks Target. :)