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GMAT blows
- Newbie | Next Rank: 10 Posts
- Posts: 4
- Joined: Tue Aug 14, 2007 2:50 pm
There were a few PS questions I could not solve on my own and would appreciate if anyone can help. Thanks!
1. If n is a multiple of 5 and n=p^2q , where p and q are prime numbers, which of the following must be a multiple of 25?
a) p^2
b) q^2
c) p*q
d) p^2*q^2
e)p^3*q
24. A certain stock exchange designates each stock w/ one-, two-, three- letter code, where each letter is selected from 26 letters of the alphabet. If the letters may be repeated and if the same letters used in a different order consistutes a different code, how many different stocks is possible to uniquesly designate with these codes?
a) 2951
b) 8125
c) 15600
d) 16302
e) 18278
Any additional insights for doing combination problems will be appreciated also
1. If n is a multiple of 5 and n=p^2q , where p and q are prime numbers, which of the following must be a multiple of 25?
a) p^2
b) q^2
c) p*q
d) p^2*q^2
e)p^3*q
24. A certain stock exchange designates each stock w/ one-, two-, three- letter code, where each letter is selected from 26 letters of the alphabet. If the letters may be repeated and if the same letters used in a different order consistutes a different code, how many different stocks is possible to uniquesly designate with these codes?
a) 2951
b) 8125
c) 15600
d) 16302
e) 18278
Any additional insights for doing combination problems will be appreciated also
