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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

saurabhmalpani
10-31-2004, 05:19 AM
E is the Ans ..

2*7!= 1440

Saurabh Malpani

neokeynesian
10-31-2004, 05:35 AM
Can u explain how u got it

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

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. :)

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.

bscout
11-24-2006, 12:24 PM
Got it. Thanks Target. :)