In a certain animal population, for each of the first three months of life, the probability that an animal will die during that month is 1/10.
For a group of 200 newborn members of the population, approximately how many would be expected to survive the first 3 months of life?
a) 140
b) 146
c) 152
d) 162
e) 170
OA after few attempts.
Gmat paper test - combined areas
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answer is B
1 in 10 will die.
20 in 200 after 1st month
18 in 180 after 2nd month
approximately 16 in 162 after 3 months
final number left will be 146
1 in 10 will die.
20 in 200 after 1st month
18 in 180 after 2nd month
approximately 16 in 162 after 3 months
final number left will be 146
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given probabity than an animal dies is 1/10 for each of the first three months
so P (animal surivies) =9/10 for each of the 3 months
so P (animal survives all the 3 months) =(9/10)^3
so nos of animals that survive 3 months = (9/10)^3 *200 = 146 approx
so ans B
so P (animal surivies) =9/10 for each of the 3 months
so P (animal survives all the 3 months) =(9/10)^3
so nos of animals that survive 3 months = (9/10)^3 *200 = 146 approx
so ans B
Regards
Samir
Samir