GMAT Prep2 problem- help please
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1/3 for me ..jaydeer44 wrote:how do I approach this problem? The answer is D.
here it goes...
assuming that 1 letter will be put into the envelope with its correct address
probability of first letter in correct envelope is 1/4
probability of second letter in wrong envelope is 1=1/3 = 2/3
probability of 3rd letter in wrong envelope is 1-1/2 = 1/2
4th letter in wrong envelope is 1
total is 1/4*2/3*1/2*1= 1/12
Since we will have 4 such combinations . total probability is
4/12 = 1/3
hope that helps