Human blood can be classified into four common blood types-A, B, AB, and O. It is also characterized by the presence (+) or absence (-) of the rhesus factor. The table shows the distribution of blood type and rhesus factor for a group of people. If one of these people who is rhesus negative (-) is chosen at random, the probability that the person has blood type B is 1/9. What is the value of x?
Correct answer: D. 8
- A. 5
- B. 6
- C. 7
- D. 8
Explanation
The correct answer is 8. In this group,1/9th of the people who are rhesus-negative have blood type B. The total number of people who are rhesus negative in the group is 7 + 2 + 1 + x, and 2 people are rhesus negative with blood type B. Therefore, 2 /(7 + 2 + 1 + x) = 1/9. Combining like terms on the left-hand side of the equation yields 2/(10+x) = 1/9. Multiplying both sides of this equation by 9 yields 18/(10+x) = 1, and multiplying both sides of this equation by (10 + x) yields 18 = 10 + x. Subtracting 10 from both sides of this equation yields 8 = x.
Last updated
About Quantitative Reasoning
Quantitative reasoning applies arithmetic and basic algebra to numerical relationships, including percentages, ratios, averages, fractions, proportions, profit and loss, rates, time, work and measurement. Questions focus on translating words into equations, choosing an efficient method and checking whether the result is numerically reasonable.
Practise Quantitative Reasoning
505 free Quantitative Reasoning MCQs from Analytical and Logical Reasoning, each with the correct answer and an explanation. Unlimited attempts, no account needed.
Exams that ask Analytical and Logical Reasoning questions like this
Analytical and Logical Reasoning is on 24 papers prepared for on TestUstad, and all of them draw the same bank, so this question is worth knowing for every one of them.
Related questions
State whether a ∈ C, if {a} ⊂ A: i: A ⊆ B ii: B ⊆ C
If 2m=4x and 2w = 8x, what is m in terms of w?
The sum of the Series will be i) Tn = 7n -5 ii) 𝑑 = −5 iii) 𝑎 = 2 iv) 𝑛 = 16 Which two statements are sufficient to solve the given question?
If Lines AB||CD, then e = ?
Find the number of degrees in angle B?I. AC < BCII. Angle BCD = 100°III. Angle A + Angle B + Angle C = 180°IV. AB = BCV. ABC is an isosceles triangle Which two statements are sufficient to answer the question?