A Jar contains 18 balls. 3 blue balls are removed from the jar and not…
2025
A Jar contains 18 balls. 3 blue balls are removed from the jar and not replaced.Now the probability of getting a blue ball is 1/5 then how many blue balls jar contains initially ?
- A.
6
- B.
10
- C.
20
- D.
11
Attempted by 24 students.
Show answer & explanation
Correct answer: A
Solution:
Let B be the initial number of blue balls.
After removing 3 blue balls, the number of blue balls becomes B - 3 and the total number of balls becomes 18 - 3 = 15.
The given probability of drawing a blue ball then is (B - 3)/15, and this equals 1/5:
(B - 3)/15 = 1/5
Solve for B: B - 3 = 15 × 1/5 = 3, so B = 3 + 3 = 6.
Answer: 6