Question 9359
it is all to do with how a question is worded to be honest. You have to follow the English of it and then act accordingly


So lets look at 2 "versions" of a question:


A. A $100 item is given a 20% discount. From this, a further 15% is taken off. What is the final sale price?


B. A $100 item is given a 35% discount. What is the sale price?


OK, A has 0.80*100 --> $80 and then 0.85*80 --> $68
or all together, 0.85*(0.80*100) --> 0.68*100


Now B has just 0.65*100 --> $65


In essence, in A, we have 20% taken from the original price and THEN 15% taken  off another "intermediate" price to arrive at $68. Whereas, in B, the full 35% is taken off the original price.


Hope this clarifies it? :-) But, yes, you are correct... it is confusing and you have to be careful AND the question setter has to be very careful with their wording too, to avoid any misunderstandings like this.


jon.