Stardust Chris
One number will be chosen randomly from each of the sets below . If x represents the chosen member of Set X and y represents the chosen member of Set Y, what is the probability that \(x/y\) will be an integer?
X = {9, 10, 11, 12}
Y = {2, 3, 4, 5}
A) 1/16
B) 3/8
C) 1/2
D) 3/4
E) 15/16
To answer such a question, you should first think about the requirement for x/y to be an Integer
Requirement: for x/y to be an integer x should be a multiple of yNow take the values of y one by one
for y=2, x can be 10 or 12 only as these are the the only numbers which are multiple of 2 in set x. Hence 2 favorable cases
for y=3, x can be 9 or 12 only as these are the the only numbers which are multiple of 3 in set x. Hence 2 favorable cases
for y=4, x can be 12 only as this is the the only number which is multiple of 4 in set x. Hence 1 favorable cases
for y=5, x can be 10 only as this is the the only number which is multiple of 5 in set x. Hence 1 favorable cases
Total Favorable cases = 2+2+1+1 = 6
Total possibilities of x/y = 4 x 4 = 16 [because there are 4 possible values of x and 4 possible values of y]
Probability = Favorable Outcomes / Total Outcomes = 6/16 = 3/8
Answer: Option