Posted by michael on .
If x is inversely proportional to y, and x=60 when y=0.5, find x when y =12

algebra 
Reiny,
x is inversely proportional to y > x = k/y
if x=60, then y=0.5
60 = k/.05
k = 3
so x = 3/y or xy = 3
when y = 12
12x = 3
x = 3/12 = 1/4
I did this very systematically, you can shorten it up a bit 
algebra 
michael,
my choices are 0.4, 25, 2.5, or 360.
so, is the answer 0.4 or 25?