ECZ 2016 · O-Level Paper 1 — Probability
There are 45 green and red marbles in a bag. Given that the probability of choosing a green marble is 2⁄5, calculate the number of green marbles in the bag.
- A. 27
- B. 9
- C. 90
- D. 18
Verified working — step 1
Run probability BACKWARDS: the probability times the total tells you how many marbles are green.The full step-by-step working and final answer are included with Premium — checked against ECZ marking standards.
Original examination question © Examinations Council of Zambia. Worked solution and commentary © G12 Titan — not to be reproduced without permission.
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