The function f is defined for each positive three-digit integer n by f(n) = 2^x3^y^5^z , where x, y and z are the hundreds, tens, and units digits of n, respectively. If m and v are three-digit positive integers such that f(m)=9f(v), them m-v=?
(A) 8
(B) 9
(C) 18
(D) 20
(E) 80
5-Day Free Trial
5-day free, full-access trial TTP
Available with Beat the GMAT members only code
MORE DETAILS
PS
This topic has expert replies
-
crazy4gmat
- Master | Next Rank: 500 Posts
- Posts: 160
- Joined: Fri Aug 22, 2008 4:54 am
- Thanked: 5 times
- GMAT Score:660
-
scoobydooby
- Legendary Member
- Posts: 1035
- Joined: Wed Aug 27, 2008 10:56 pm
- Thanked: 104 times
- Followed by:1 members
(D)
f(n)=2^x 3^y 5^z
f(v)=2^1 3^1 5^1 say for simplicity, or v is 111
f(m)=9*2^1 3^1 5^1= 2^1 3^3 5^1 (9^=3^2) or m=131
now m-v=131-111=20
f(n)=2^x 3^y 5^z
f(v)=2^1 3^1 5^1 say for simplicity, or v is 111
f(m)=9*2^1 3^1 5^1= 2^1 3^3 5^1 (9^=3^2) or m=131
now m-v=131-111=20
-
vittalgmat
- Legendary Member
- Posts: 621
- Joined: Wed Apr 09, 2008 7:13 pm
- Thanked: 33 times
- Followed by:4 members
this q was previously discussed. If I remember right, the person who posted this q made a typo. He mentioned the q as f(n) = 2x3y5z. Pls search.
cheers
-V
cheers
-V
