WAEC Further Mathematics Past Questions & Answers - Page 116

576.

A mass of 75kg is placed on a lift. Find the force exerted by the floor of the lift on the mass when the lift is moving up with constant velocity. \([g = 9.8ms^{-2}]\)

A.

750N

B.

745N

C.

735N

D.

98N

Correct answer is C

Net force = Upward force - weight

\(ma = F - mg\)

With constant velocity, acceleration = 0, therefore, ma = 0

\(\therefore F = mg = 75 \times 9.8 = 735N\).

577.

Marks 0 1 2 3 4 5
Number of candidates 6 4 8 10 9

3

The table above shows the distribution of marks scored by students in a test. Find the interquartile range of the distribution.

A.

4

B.

3

C.

2

D.

1

Correct answer is B

No explanation has been provided for this answer.

578.

Marks 0 1 2 3 4 5
Number of candidates 6 4 8 10 9 3

The table above shows the distribution of marks scored by students in a test. How many candidates scored above the median score?

A.

3

B.

12

C.

22

D.

30

Correct answer is B

The total number of candidates = 40, therefore, the median occurs as the average between the 20th and 21st candidates. = \(\frac{3+3}{2} = 3\)

Number of candidates that scored above 3 : 9 + 3 = 12.

579.

Given that \(r = 2i - j\), \(s = 3i + 5j\) and \(t = 6i - 2j\), find the magnitude of \(2r + s - t\).

A.

\(\sqrt{15}\)

B.

4

C.

\(\sqrt{24}\)

D.

\(\sqrt{26}\)

Correct answer is D

\(r = 2i - j , s = 3i + 5j , t = 6i - 2j\)

\(2r + s - t = 2(2i - j) + (3i + 5j) - (6i - 2j) = i + 5j\)

\(|2r + s - t| = \sqrt{1^{2} + 5^{2}} = \sqrt{26}\)

580.

Given the statements:

p : the subject is difficult

q : I will do my best

Which of the following is equivalent to 'Although the subject is difficult, I will do my best'?

A.

\(p \vee q\)

B.

\(\sim p \vee q\)

C.

\(p \wedge (\sim q)\)

D.

\( p \wedge q\)

Correct answer is D

No explanation has been provided for this answer.