Hi, I'm not able to figure out when to use the number format (eg: 1234NNN) and when to use the yes/no (eg: YYYYNNN) format. For example, consider the 2 problems provided below : 1> The principal of a high school needs to schedule observations of 6 teachers. She plans to visit one teacher each day...

Sorry, I didn't adhere to the posting rules. The problems can be found in Chapter 4, page 61 (Combinatorics problem set : Q 9 & 10). I've posted two problems because a comparison was needed. I'll first provide the solution to these problems(as given in the solution set of the book) and then pose...

I'm not sure if the answer should be B. The answer I think is E. From the 2nd statement, we only get xy < 1 : Divide both sides of the inequality by (x^8)(y^8) Thus, it looks something like : (x^9)(y^9) / (x^8)(y^8) < (x^8)(y^8) / (x^8)(y^8) Therefore, xy < 1 ..... which is not what is requ...

A certain quantity of 40% solution is replaced with 25% solution such that the new concentration is 35%. What is the fraction of the solution that was replaced? (A) 1/4 (B) 1/3 (C) 1/2 (D) 2/3 (E) ¾ Ans: Let X be the fraction of solution that is replaced. Then X*25% + (1-X)*40% = 35% Solving, you g...

Are you sure the answer is C ??? I was getting D as the answer, each statement alone is sufficient.

Let the increase per year = x Therefore, height of the tree at the end of the 6th year is : 4 + 6x Also, it is given that : At the end of 6th year, the tree was 1/5 taller than it was at the end of 4th year. Height of the tree at the end of the 4th year = 4 + 4x The tree was 1/5 taller than it was a...

I'm sorry Ben, I understand your concern. This was something I found on the beatthegmat forum. Hope this helps.