A bag contains 7 white and 9 red balls (total 16). One ball is drawn at random. What is the probability that it is white?

Difficulty: Easy

Correct Answer: 7/16

Explanation:

Introduction / Context:Single-draw colour problems require counting favourable outcomes (white balls) and dividing by the total number of balls, assuming all are equally likely to be drawn.

Given Data / Assumptions:

  • White = 7, Red = 9, Total = 16.
  • Uniform random draw.

Concept / Approach:P(white) = white/total = 7/16.

Step-by-Step Solution:Favourable = 7 white balls.Total = 16 balls.Probability = 7/16.

Verification / Alternative check:P(red) = 9/16; 7/16 + 9/16 = 1 confirms consistency.

Why Other Options Are Wrong:1/16 and 7/52 confuse totals or a 52-card deck; 1/52 is irrelevant.

Common Pitfalls:Transferring fractions from card problems to urn problems.

Final Answer:7/16

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