TestMagic Forums - View Single Post

nerrad_oh · 07-21-2008, 05:47 AM

IMO answer is A = 8 ??

Given f(n) = 2x3y5z. So if n = 123, this means 2(1)*3(2)*5(3)= 180.

Given f(m) = 9*f(v). Just assume 3-digit number m = abc and v = def.

f(m) = 9*f(v)
2a3b5c = 9*[2d3e5f]
(2*3*5)abc = 9*(2*3*5)def
30abc=9*30def
abc=9*def

Now m-v = abc-def = 9*def-def = 8.

But I look at RamN answer and that seems to make sense too

But doesn't that answer assumes n=111? If n=222, will the same holds true ?

07-21-2008, 05:47 AM	#8 (permalink)
nerrad_oh Eager! Join Date: Jul 2008 Posts: 30	IMO answer is A = 8 ?? Given f(n) = 2x3y5z. So if n = 123, this means 2(1)3(2)5(3)= 180. Given f(m) = 9f(v). Just assume 3-digit number m = abc and v = def. f(m) = 9f(v) 2a3b5c = 9[2d3e5f] (235)abc = 9(235)def 30abc=930def abc=9def Now m-v = abc-def = 9*def-def = 8. But I look at RamN answer and that seems to make sense too But doesn't that answer assumes n=111? If n=222, will the same holds true ?