Question

A class consists of 50 students out of which there are 10 girls. in the class 2 girls and 5 boys are rank holders in an examination. if a student is selected at random from the class and is found to be a rank holder, what is the probability that the selected student is a girl? solution

Answer 1

Total no. of rank holders =2+5 = 7
Total no. of student = 50
Probability of getting a rank holder = 7/50
No. of girl rank holder = 2
Probability of getting a girl rank holder
= 2/7 of 7/ 50
= 2/50
= 1/25

Answer 2

Step-by-step explanation:

• So there are 50 students
• Out of which 10 are girls and so remaining 40 are boys. (50 – 10)
• Now out of the 10 girls two are rank holders.
• Also out of 40 boys 5 are rank holders,
• So total there are 7 rank holders.
• Now let m be the event as a girl being selected.
• So let n be the rank holder being selected be p(n) = 7/50
• P(m ∩ n) = 2/50 (two out of 50)
• We need to find the probability of girl being selected is a rank holder.
• So conditional probability P(m/n) = P (m ∩ n) / P(n)
•              = 2/50 / 7/50
•              = 2/7
• Therefore the probability will be 2/7

Reference link will be

https://brainly.in/question/79371?