X percent of Y percent of Z is decreased by Y percent. What is the result?
A) (100xyz - xy^2Z) / 1,000,000
B) (XZ-Y) / 100
C) (XZ-Y) / 10,000
D) (XYZ - 2Y) / 100
E) (XYZ - 2Y) / 10,000
I don't understand on these types of problems when to solve by direct algebra or "picking numbers" as the MGMAT book
says. I calculated this probably like this:
( (x/100) * (y/100) * z ) - (y/100) = (xyz/10,000) - (y/100) = (xyz - 100y) / 10,000
MGMAT picks numbers out of thin air which I'm not the greatest at. Is there anyway to solve this with direct math?
3. The above value is decreased by