ECZ 2015 · GCE Paper 2 · Question 6 — Sets
Question from ECZ 2015 · GCE Paper 2 · Question 6
(a) At Gender Technical Secondary School, a group of 70 girls take optional subjects as illustrated in the Venn diagram below.
(a(i)) Calculate the value of x.[2]
Verified working — step 1
The four Venn regions add to the 70 pupils.(a(ii)) Find the number of girls who take
(a(ii)(a)) History only,[1]
Verified working — step 1
History only is the region 3x - 5.(a(ii)(b)) Commerce.[1]
Verified working — step 1
R.E lies inside Commerce, so Commerce is every region within its circle.(b) A box has 14 identical balls, three of which are blue. Two balls are drawn at random from the box, one after the other without replacement. Calculate the probability that
(b(i)) the two balls are both blue,[2]
Verified working — step 1
14 balls in total with 3 blue, drawn WITHOUT replacement.(b(ii)) at least one ball drawn is blue.[3]
Verified working — step 1
"At least one blue" is easier as 1 minus "no blue at all".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