ECZ 2017 · GCE Paper 2 · Question 3 — Probability
A box has 10 bulbs of which 3 are faulty; two bulbs are drawn at random one after the other (without replacement). The Venn diagram shows tourist attractions visited by students: Victoria Falls only = 6, Victoria∩Mambilima only = 2, all three = 10, Victoria∩Gonya only = 4, Mambilima only = 2y + 1, Mambilima∩Gonya only = 1, Gonya Falls only = 8.
(a(i)) Find the probability that both bulbs are good.[2]
Verified working — step 1
Good bulbs = 7, total = …(a(ii)) Find the probability that one bulb is faulty and the other is good.[3]
Verified working — step 1
P(1st faulty, 2nd good) = 310× 79= 2190(b(i)) Find the value of y, if 7 students visited Mambilima Falls only.[2]
Verified working — step 1
Mambilima only = 2y+1 = 7(b(ii)(a)) How many students visited Victoria Falls but not Gonya Falls?[1]
Verified working — step 1
Visited Victoria but not Gonya = …(b(ii)(b)) How many students visited two tourist attractions only?[1]
Verified working — step 1
Two attractions only = …(b(ii)(c)) How many students visited one tourist attraction only?[1]
Verified working — step 1
One attraction only = …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.
Have a different question?
Search it — if it is from a past paper or a school mock, chances are we have it worked out, or one that uses the same method.
Search any past-paper question