ECZ 2025 · GCE Paper 2 · Question 3 — Matrices

Question from ECZ 2025 · GCE Paper 2 · Question 3

(a) Given that matrix P = 4-211, find the

(a(i)) determinant of matrix P,[2]

Verified working — step 1

The determinant of matri…

(a(ii)) inverse of matrix P.[2]

Verified working — step 1

For abcd the inverse is (1det) d-b-ca.

(b) A box contains 6 white circuit breakers and 4 black circuit breakers, all identical in appearance. A circuit breaker is selected at random from the box and not replaced. A second circuit breaker is then selected. Find the probability that both circuit breakers selected are

(b(i)) white,[2]

Verified working — step 1

10 breakers in the box: 6 white and 4 black, drawn WITHOUT replacement.

(b(ii)) of different colours.[3]

Verified working — step 1

"Different colours" happens two ways: white then black, or black then white.

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

More Matrices questions from past papers