In a school, sixty percent of the students are girls and thirty five percent…
2026
In a school, sixty percent of the students are girls and thirty five percent of the girls are poor. If a student is randomly selected, what is the probability of selecting a poor girl student?
- A.
60%
- B.
35%
- C.
21%
- D.
None
Attempted by 58 students.
Show answer & explanation
Correct answer: C
Concept: When an outcome requires two conditions to both hold (here, being a girl AND being poor), the probability of both together equals the probability of the first condition multiplied by the conditional probability of the second condition given the first: P(A and B) = P(A) × P(B | A).
Application: Take the total number of students to be 100, so percentages convert directly into counts.
Number of girls = 60% of 100 = 60.
Number of poor girls = 35% of the girls = 0.35 × 60 = 21.
Probability of selecting a poor girl = 21 / 100 = 21%.
Cross-check: Multiplying the two percentages directly gives the same result: 60% × 35% = 0.60 × 0.35 = 0.21 = 21%, confirming the count-based calculation above.
Result: The probability of selecting a poor girl is 21%.