Guys,
I asked this question to the MGMAT staff, but guess they are inundated by other posts.
I always use the 2 set matrix method for solving set questions. however, i feel it does not work always. I am posting the below question.
Can some of you experts pls help me? I need to get this funda cleared. My GMAT is next Thursday.
I am copy pasting the question asked in that forum here.
------------------------------------------------------
Ron,
You say that always use the 2 set matrix and not the venn unless you want to make life harder.
I am attaching below 3 problems. All of them are from the GMAT Prep software. I have tried using the 2 set matrix but it does not work (at least for me). I also tried 'googling' these questions and the solutions are either the venn diagram or the T = A+B-Both+Neither formula, which i understand is nothing but the venn diagram algebraic representation.
If you could please throw some light, I will indeed be glad. Perhaps i am missing the concept or doing something wrong, but this if you reply, it will indeed help.
1) A seminar consisted of morning session and afternoon session. If each of the 128 people attending attended at least one of the two sessions, how many of the people attended the morning session only?
a. ¾ attended both sessions
b. 7/8 attended the afternoon session
----------------
2]If 75 percent of the guests at a certain banquet ordered dessert, what percent of the guests ordered coffee?
(1) 60 percent of the guests who ordered dessert also ordered coffee.
(2) 90 percent of the guests who ordered coffee also ordered dessert.
---------------
3) Last year in a group of 30 businesses, 21 reported a net profit and
15 had investments in foreign markets. How many of the businesses
did not report a net profit nor invest in foreign markets last year?
(1) last year 12 of the 30 businesses reported a net profit and had investments in foreign markets.
(2) last year 24 of the 30 businesses reported a net profit or invested in
foreign markets, or both.
--------------------
I asked this question to the MGMAT staff, but guess they are inundated by other posts.
I always use the 2 set matrix method for solving set questions. however, i feel it does not work always. I am posting the below question.
Can some of you experts pls help me? I need to get this funda cleared. My GMAT is next Thursday.
I am copy pasting the question asked in that forum here.
------------------------------------------------------
Ron,
You say that always use the 2 set matrix and not the venn unless you want to make life harder.
I am attaching below 3 problems. All of them are from the GMAT Prep software. I have tried using the 2 set matrix but it does not work (at least for me). I also tried 'googling' these questions and the solutions are either the venn diagram or the T = A+B-Both+Neither formula, which i understand is nothing but the venn diagram algebraic representation.
If you could please throw some light, I will indeed be glad. Perhaps i am missing the concept or doing something wrong, but this if you reply, it will indeed help.
1) A seminar consisted of morning session and afternoon session. If each of the 128 people attending attended at least one of the two sessions, how many of the people attended the morning session only?
a. ¾ attended both sessions
b. 7/8 attended the afternoon session
----------------
2]If 75 percent of the guests at a certain banquet ordered dessert, what percent of the guests ordered coffee?
(1) 60 percent of the guests who ordered dessert also ordered coffee.
(2) 90 percent of the guests who ordered coffee also ordered dessert.
---------------
3) Last year in a group of 30 businesses, 21 reported a net profit and
15 had investments in foreign markets. How many of the businesses
did not report a net profit nor invest in foreign markets last year?
(1) last year 12 of the 30 businesses reported a net profit and had investments in foreign markets.
(2) last year 24 of the 30 businesses reported a net profit or invested in
foreign markets, or both.
--------------------
