soussou

I agree with Greycellz, If X is total amount of magazines sold, Revenue of A = (p/100)*X*1 Hence, r/100 = (p/100)*X*1 / ((p/100)*X*1 + (1- p/100)*X*1.25) Simplifications result in D. Now that looks simple to me now but I was blured for a while on it, is that a difficult level question or not?

I dont see why you are adding, I believe it is only the multiplication of perfect squares...10*10 will give two zeroes...so will 20*20, 30*30, 40*40...100*100, count all the 0s once and put them at the end...

Go for it, beyond this point it is all about profile and what you can bring to your class...

To add to eventual ways of thought, when you have more than one ring per finger, why don't you count the order in which you are waring those rings?

Put it in the form of a table and just add and substract on each side 1-3 1-9 10-30 4-36 8- 24 6-42 etc.