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Question
In a medical examination of students of a class, the following blood groups are recorded:
| Blood group | A | AB | B | O |
| Number of students | 10 | 13 | 12 | 5 |
A student is selected at random from the class. The probability that he/she has blood group B, is:
Options
`1/4`
`13/40`
`3/10`
`1/8`
Solution
`bb(3/10)`
Explanation:
Total number of students in a medical examination, n(S) = 40
Number of persons who have B blood group, n(E) = 12
∴ Probability that he/she has blood group B = `(n(E))/(n(S)) = 12/40 = 3/10`
Hence, the probability that he/she has blood group B is `3/10`.
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