Guys I was solving a question and I made this silly mistake.I corrected myself but was hoping somebody throw some light on where my concept was wrong.
Suppose 2/3 out of N employees dring regular coffee.Out of these 2/5 add cream.How many of the employees who drink regular coffee do not add cream?
Ans: 2/3n - 2/5n = 4n/15.(ans.)
What I did was:If 2/5 add cream,then 3/5 do not add cream.So 3/5 x 2/3n = 2/5n
Catch some light.
Sorry, can't help !
When you say 2/3 employees of total. It is 2N/3
When you calculated 3/5 = do not add cream. It means 3N/5
do not add cream. It's 3/5
of total employees & not 3/5
of 'the employees who drink regular coffee'.
Let's say Y = 2N/3
= employees who drink regular coffee.
You are supposed to multiply 3/5
to 'N' not to Y.
P.S. You can draw a venn diagram, if you are still confused. I am too lazy to draw one on Monday morning. :yawn:
I am ready to fall, but not before I fly.