Posted by Izzy on Monday, October 1, 2012 at 4:30pm.
Find a three digit number so that when the digita of the number Are added together the total is one fifth of the product of the digits

Maths  Steve, Monday, October 1, 2012 at 4:45pm
if the digits are a,b,c then
5(a+b+c) = abc
c = 5(a+b)/(ab5)
so, ab must be greater than 5,
ab cannot be 6, since then a+b > 5
if ab=7, then 5(8)/2 = 20 > 10
if ab=8, then c = 5(6)/3 = 10 too big
if ab=9, then c=5(6)/4 = not integer
if ab=10, then c=5(7)/5 = 7
257: 2+5+7 = 14 = 2*5*7/5