Bunuel wrote:
A group of friends went to an ice-cream parlour and ordered only two types of ice-cream - chocolate and strawberry. Of the people in the group, at least one person ate only one type ice-cream, some people ate both types of ice-cream and at least one person did not eat any type of ice-cream. Did more people eat chocolate ice-cream than strawberry ice-cream?
(1) The ratio of the number of people who ate chocolate ice-cream to people who ate strawberry ice-cream was greater than the ratio of the total number of people who went to ice-cream parlour to the number of people who did not eat any type of ice-cream.
(2) The number of people who ate only one type of ice-cream is greater than the number of people who ate strawberry ice-cream.
You can use 2*2 matrix for such questions.
....................C........nC.........TotalS..................a..........b............a+b
nS................c..........d.............c+d
Total..........a+c.......b+d......a+b+c+d
GivenQuote:
a) at least one person ate only one type ice-cream => \(b+c\geq 1\)
b) some people ate both types of ice-cream => \(a\geq 1\)
c) at least one person did not eat any type of ice-cream => \(d\geq 1\)
We are looking for -
Is a+c>a+b ? Or
Is c>b?
Statement I
The ratio of the number of people who ate chocolate ice-cream
(a+c) to people who ate strawberry ice-cream
(a+b) was greater than the ratio of the total number of people who went to ice-cream parlour
(Total) to the number of people who did not eat any type of ice-cream
(d).
Thus, \(\frac{a+c}{a+b}>\frac{a+b+c+d}{d}= \frac{a+b+c}{d} + \frac{d}{d} = \frac{a+b+c}{d} +1>1\)
So \(\frac{a+c}{a+b}>1.....a+c>a+b\)
Sufficient
Statement II
The number of people who ate only one type of ice-cream
(b+c) is greater than the number of people who ate strawberry ice-cream
(a+b).
\(b+c>a+b....c>a\)
But we do not know anything about b!
Insufficient
A