GATE CSE 2024 Session 1 Q63: Both balls red given the first is red (without replacement)
- Engineering Mathematics
- 2 marks
- NAT
- No negative marking
Question
A bag contains 10 red balls and 15 blue balls. Two balls are drawn randomly without replacement. Given that the first ball drawn is red, the probability (rounded off to 3 decimal places) that both balls drawn are red is _________
Try it: numerical answer: type the value
Show answer and explanation
Answer: 0.37 to 0.38 (official GATE 2024 final answer key)
Concept used: Conditional probability: given the first is red, only the second draw matters.
First step: After one red is removed, 9 of the remaining 24 balls are red.
Full step-by-step solution
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Source: official GATE 2024 Session 1 CS question paper and final answer key, organised by IISc Bangalore. Question paper · Answer key
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