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DATA Sufficiency Probability

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DATA Sufficiency Probability

by Robinmrtha » Sun Jun 07, 2009 5:44 pm
A critical meeting on the subprime crisis has been scheduled. A group of investment bankers, whose mean age is 59, must attend. Each banker must flip a coin to choose whether to wear either a pinstripe suit or a solid suit. How many executive are attending the meeting?

1) The sum of their ages is a multiple of 3

2) The probability of all of the bankers wearing a solid suit is less than 1/3 and greater than 1/24

The answer is C how?
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by Claret » Sun Jun 07, 2009 6:06 pm
statement 1 : Insufficient
this implies the no. of executives attending the meeting is a multiple of 3 i.e it cud be 3, 6, 9....

statement 2 : Insufficient

probability of an executive to wear a solid suit is 1/2
therefore probability of n executives to wear a solid suit = (1/2)^n
1/24<(1/2)^n<1/3

Statement 1 & 2 give
n = 3

therefore ANS C
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by shashank.mehra » Thu Jun 18, 2009 12:33 pm
Claret wrote:statement 1 : Insufficient
this implies the no. of executives attending the meeting is a multiple of 3 i.e it cud be 3, 6, 9....

statement 2 : Insufficient

probability of an executive to wear a solid suit is 1/2
therefore probability of n executives to wear a solid suit = (1/2)^n
1/24<(1/2)^n<1/3

Statement 1 & 2 give
n = 3

therefore ANS C
Pl elaborate on how can you deduce from Statement 1 that the number of Exec attending the conf is a multiple of three... even if four guys are attending the sum of their ages can be a multiple of 3.
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by Claret » Thu Jun 18, 2009 12:45 pm
ok..

it is given in the question stem that the mean of the ages of the executives is 59
sum of ages = no. of executives * mean age of the executives
from statement 1 :
sum of ages =(multiple of 3) *59
therefore we can conclude that the sum of the ages is a multiple of 3..

hope it helps..
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by shashank.mehra » Fri Jun 19, 2009 5:52 am
thanx man
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