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Example Questions
Example Question #3171 : Gmat Quantitative Reasoning
For Data Sufficiency questions, select either A, B, C, D, E based on the following rubric:
- A) statement 1 alone is sufficient, but statement 2 alone is not sufficient to answer the question
- (B) statement 2 alone is sufficient, but statement 1 alone is not sufficient to answer the question
- (C) both statements taken together are sufficient to answer the question, but neither statement alone is sufficient
- (D) each statement alone is sufficient
- (E) statements 1 and 2 together are not sufficient, and additional data is needed to answer the question
When a delectable baked treat is selected at random from the baker's case, what is the probability that it will be kirsch flavored?
1. One half of the treats are peanut-butter flavored.
2. There are one third as many kirsch treats as peanut-butter treats.
B
C
D
A
E
C
Remember, you do not have to SOLVE the data sufficiency problems. In other words, you do not have to calculate the exact probability of getting a kirsch-flavored (cherry liquor) treat. You just need to determine how many of the statements are NECESSARY to derive the answer.
The first statement by itself is not sufficient, because knowing that half of the treats are peanut butter flavored does not tell you the proportion that are kirsch flavored.
The second statement is not sufficient, because comparing the proportion of kirsch treats to peanut-butter treats won't help you find the probability of getting a kirsch treat unless you know the ratio of peanut-butter treats in the case.
But, if we put the two pieces of information together, we can solve the problem. Statement 1 tells us the proportion of peanut-butter treats, and statement 2 tells us how many kirsch treats there are compared to peanut-butter treats.
Therefore, the correct answer is C.
Example Question #1061 : Data Sufficiency Questions
Anna is about to pick a fruit for her snack from a basket of apples and oranges. What is the probability Anna picks an apple?
(1) The basket contains fruits.
(2) Half of the fruits in the basket are oranges.
C: BOTH statements TOGETHER are sufficient, but NEITHER statement ALONE is sufficient
B: Statement (2) ALONE is sufficient, but statement (1) ALONE is not sufficient
E: Statements (1) and (2) TOGETHER are not sufficient
A: Statement (1) ALONE is sufficient, but statement (2) ALONE is not sufficient
D: EACH statement ALONE is sufficient
B: Statement (2) ALONE is sufficient, but statement (1) ALONE is not sufficient
Let P(A) be the probability of Anna picking an apple and P(O) be the probability of Anna picking an orange. We need to evaluate each statement individually first:
(1) gives us the total number of fruits, but no indication as to the number of each fruit, so we cannot determine probabilities form (1) alone
(2) gives us the proportion of oranges. Let N be the total number of fruits, A the number of apples and O the number of oranges. We have:
We also know that .
We can rewrite this last equation as follow:
or
We know that P(A) = A / N and from statement (2) we get
which we can simplify to find P(A)
Therefore the right answer is B.
Example Question #1062 : Data Sufficiency Questions
What is the probability that a randomly selected person in a sample of 100 adults is left handed?
(1) The number of left handed adults in the sample represents one fourth of the number of right handed adults in the sample.
(2) All of the women in the sample are right-handed.
Statement (1) ALONE is sufficient, but Statement (2) ALONE is not sufficient
Statement (2) ALONE is sufficient, but Statement (1) ALONE is not sufficient
Both statements TOGETHER are sufficient, but NEITHER statement ALONE is sufficient
Each statement ALONE is sufficient.
Both statements TOGETHER are not sufficient.
Statement (1) ALONE is sufficient, but Statement (2) ALONE is not sufficient
Using Statement (1), we can write the following equation:
Let x be the number of left handed people in the sample. 100-x is then the number of right handed people in the sample.
Therefore, the probability that a randomly selected person in the sample is left handed is:
Therefore Statement (1) is sufficient to answer the question
Statement (2) indicates that all women in the sample are right handed. This statement is not useful as it does not give the total number of right handed people in the sample.
Therefore, Statement (2) is not sufficient by itself to answer the question.
Only Statement (1) ALONE is sufficient.
Example Question #3171 : Gmat Quantitative Reasoning
One of the managers in a certain company is to be selected at random to represent the company at a national conference. What is the probability that a woman will be selected to represent the company?
(1) One third of the managers in the company are women.
(2) Half of the employees in the company are women.
Statement (2) ALONE is sufficient, but Statement (1) ALONE is not sufficient.
Statement (1) ALONE is sufficient, but Statement (2) ALONE is not sufficient.
Statements (1) and (2) TOGETHER are not sufficient.
Each Statement ALONE is sufficient.
Both statements TOGETHER are sufficient, but NEITHER statement ALONE is sufficient.
Statement (1) ALONE is sufficient, but Statement (2) ALONE is not sufficient.
(1) One third of the managers in the company are women.
Therefore the probability that the manager selected at random is a woman is .
Statement (1) alone is sufficient.
(2) Half of the employees in the company are women.
Even though half of the company's employees are women, this statement doesn't give the proportion of women who hold a manager job. Therefore, Statement (2) is not sufficient.
Example Question #3172 : Gmat Quantitative Reasoning
What is the probability that a randomly selected employee at a company have a MBA degree?
(1) Employees have a MBA degree.
(2) percent of employees do not have a MBA degree.
Statement (2) ALONE is sufficient, but Statement (1) ALONE is not sufficient.
Statements (1) and (2) TOGETHER are not sufficient.
Both statements TOGETHER are sufficient, but NEITHER statement ALONE is sufficient.
Statement (1) ALONE is sufficient, but Statement (2) ALONE is not sufficient.
Each Statement ALONE is sufficient.
Statement (2) ALONE is sufficient, but Statement (1) ALONE is not sufficient.
(1) 150 Employees have a MBA degree.
Since we do not know the number of employees at the company, we cannot determine the probability of employees who have an MBA degree. Statement (1) is not sufficient.
(2) 70 percent of employees do not have a MBA degree.
We can then determine the percentage of employees with an MBA degree as 30 percent. Therefore the probability of employees who have an MBA degree is 0.3.
Statement (2) ALONE is sufficient.
Example Question #33 : Discrete Probability
An insurer is trying to determine the probability of policyholders who had an accident this year.
(1) Of all policyholders, did not have an accident.
(2) Of the policyholders who had an accident, received a claim payment.
Both statements TOGETHER are sufficient, but NEITHER statement ALONE is sufficient.
Statement (1) ALONE is sufficient, but Statement (2) ALONE is not sufficient.
Statements (1) and (2) TOGETHER are not sufficient.
Each Statement ALONE is sufficient.
Statement (2) ALONE is sufficient, but Statement (1) ALONE is not sufficient.
Statement (1) ALONE is sufficient, but Statement (2) ALONE is not sufficient.
(1) Of all 1200 policyholders, 1050 did not have an accident.
From statement (1), we can determine that 150 policyholders had an accident. We can then calculate the probability as .
Statement (1) alone is sufficient.
(2) Of the policyholders who had an accident, 90% received a claim payment.
Statement (2) is irrelevant since we are not interested in the probability of policyholders who received a claim payment.
Statement (2) is not sufficient.
Example Question #34 : Discrete Probability
A store owner is trying to determine the probability of defective light bulbs he holds in his inventory.
(1) out of light bulbs are defective.
(2) After checking half of the inventory, the store owner finds defective light bulbs.
Statements (1) and (2) TOGETHER are not sufficient.
Statement (1) ALONE is sufficient, but Statement (2) ALONE is not sufficient.
Statement (2) ALONE is sufficient, but Statement (1) ALONE is not sufficient.
Both statements TOGETHER are sufficient, but NEITHER statement ALONE is sufficient.
Each Statement ALONE is sufficient.
Statement (1) ALONE is sufficient, but Statement (2) ALONE is not sufficient.
(1) 15 out of 150 light bulbs are defective.
Using statement (1), the probability of defective light bulbs is
Statement (1) is sufficient.
(2) After checking half of the inventory, the store owner finds 10 defective light bulbs
We do not know the number of defective light bulbs in all the inventory and we do not know the number of light bulbs in inventory.
Statement (2) is not sufficient.
Example Question #1063 : Data Sufficiency Questions
What is the number of unemployed adults in City A?
(1) The number of adults in City A is .
(2) Three fourth of adults in City A are employed.
Statements (1) and (2) TOGETHER are not sufficient.
Each Statement ALONE is sufficient.
Statement (2) ALONE is sufficient, but Statement (1) ALONE is not sufficient.
Both statements TOGETHER are sufficient, but NEITHER statement ALONE is sufficient.
Statement (1) ALONE is sufficient, but Statement (2) ALONE is not sufficient.
Both statements TOGETHER are sufficient, but NEITHER statement ALONE is sufficient.
(1) The number of adults in City A is 1000.
Statement (1) is not sufficient to find the number of unemployed adults in City A.
(2) Three fourth of adults in City A are employed.
This statement tell us that of adults are unemployed. However, without knowing the number of adults in City A we cannot determine the number of unemployed adults in City A. Statement (2) alone is not sufficient.
Combining both statements, we find that the number of unemployed adults is of 1000 which is 250.
Both statements together are sufficient, but neither statement alone is sufficient.
Example Question #3181 : Gmat Quantitative Reasoning
What is the probability that a randomly selected man in a sample of men has a beard?
(1) Half of the men in the sample do not have a beard.
(2) There are men with a beard in the sample.
Statements (1) and (2) TOGETHER are not sufficient.
Each Statement ALONE is sufficient.
Both statements TOGETHER are sufficient, but NEITHER statement ALONE is sufficient.
Statement (1) ALONE is sufficient, but Statement (2) ALONE is not sufficient.
Statement (2) ALONE is sufficient, but Statement (1) ALONE is not sufficient.
Statement (1) ALONE is sufficient, but Statement (2) ALONE is not sufficient.
(1) Half of the men in the sample do not have a beard.
This statement implies that the other half of the men in the sample have a beard. Therefore, the probability that a randomly selected man in the sample has a beard is 0.5.
Statement (1) alone is sufficient.
(2) There are 100 men with a beard in the sample.
Statement (2) gives us the number of men who have a beard in the sample but without knowing the number of men in the sample, we cannot find the probability of men who have a beard.
Statement (2) is not sufficient.
Example Question #3182 : Gmat Quantitative Reasoning
What is the probability that a randomly selected student enrolled at a university will be a graduate student?
(1) of the students enrolled at the university are graduate students.
(2) Only of the students enrolled are graduate students.
Statement (2) ALONE is sufficient, but Statement (1) ALONE is not sufficient.
Statement (1) ALONE is sufficient, but Statement (2) ALONE is not sufficient.
Both statements TOGETHER are sufficient, but NEITHER statement ALONE is sufficient.
Statements (1) and (2) TOGETHER are not sufficient.
Each Statement ALONE is sufficient.
Statement (2) ALONE is sufficient, but Statement (1) ALONE is not sufficient.
(1) 1000 of the students at the university are graduate students.
Statement (1) alone is not sufficient because we don't know the total number of students enrolled at the university.
(2) Only 20% of the students enrolled are graduate students.
Statement (2) gives the probability of graduate students enrolled at that university as 20%(0.2).
Statement (2) Alone is sufficient.