confuse them

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confuse them

by sanju09 » Sat Feb 21, 2009 4:50 am
M = {-6, -5, -4, -3, -2}
T = {-2, -1, 0, 1, 2, 3}

If an integer is to be randomly selected from set M above and an integer is to be randomly selected from set T above, what is the probability that the product of the two integers will be negative?

A. 0
B. 1/3
C. 2/5
D. 1/2
E. 3/5

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by sureshbala » Sat Feb 21, 2009 5:38 am
Since every element of set M is negative, we have to select only positive numbers from the set T for the product to be negative. So we can choose one number from M in 5 ways and the number from T in 3 ways.

Hence probability is 15/30 = 1/2