The function f is defined for each positive three-digit integer n by f(n) = 2^x3^y5^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), then m-v = ?
A. 8
B. 9
C. 18
D. 20
E. 80
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tough math question...help
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liferocks
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It is mentioned in the question thatsan2009 wrote:how did you know that x, y and z are digits of m as well?
for each positive three-digit integer n by f(n) = 2^x3^y5^z--1, where x, y and z
are the hundreds, tens, and units digits of n
since
f(v)=9*(2^x3^y5^z)=2^x3^(y+2)5^z --2
comparing 1 with 2 we can say that in v , x, y+2 and z
are the hundreds, tens, and units digits
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