BREAKING: Target Test Prep releases Brand New 2026 On Demand GMAT prep course

Redeem

What is answer .. why statement 2 can't give answer?

Expert replies
by vr4indian » Tue Sep 16, 2008 5:47 am
50% of the people in a certain city have a Personal Computer and an Air-conditioner . What percent of people in the city have a personal computer but not an Air-conditioner.

(1) 60% of the people in the city have a Personal Computer.

(2) 70% of the people in the city have an Air-conditioner.

A. Statement (1) ALONE is sufficient but Statement (2) ALONE is not sufficient.
B. Statement (2) ALONE is sufficient but Statement (1) ALONE is not sufficient.
C. BOTH Statements TOGETHER are sufficient, but NEITHER Statement alone is sufficient.
D. Each Statement ALONE is sufficient.
E. Statements (1) and (2) TOGETHER are NOT sufficient.
:shock:
Join the discussion
Source: — Data Sufficiency |

by krishnamurthyu » Tue Sep 16, 2008 7:56 am
Given:
N(Pc & Ac ) 50%

Asked:
NPc & ~Ac = ?

1. NPc = 60%
N (Pc & ~Ac) = Npc - N(Pc & Ac)
=60% - 50%
=10%
Ans:A or D

2. NAc = 70%
Here we dont know,N(Pc U Ac ) = 100% , i.e is not mentioned.
Hence we can't assume ( There could be possible this survery has TV also then Ac +Pc+Tv = 100%, even then with condition-1, we can identiy N (Pc & ~Ac)% )
N(Pc U Ac) = 100%, it could be 80% or 90%,Hence we can't apply:
N(Pc U Ac) = N(Pc) + N (Ac) - N (Pc & Ac).

Hence. Ans : A
Join the discussion

by 4meonly » Tue Sep 16, 2008 9:31 am
We dont know how many people do not have neither PC nor AC
Join the discussion