Year : 
2003
Title : 
Mathematics (Core)
Exam : 
WASSCE/WAEC MAY/JUNE

Paper 1 | Objectives

31 - 40 of 46 Questions

# Question Ans
31.

In a ∆ XYZ, /YZ/ = 6cm YXZ = 60o and XYZ is a right angle. Calculate /XZ/in cm, leaving your answer in surd form

A. 2√3

B. 4√3

C. 6√3

D. 12√3

Detailed Solution

\(sin \theta = \frac{opp}{hyp}\\
sin 60^o = \frac{|YZ|}{|XZ|}=\frac{6}{P}\\
P sin 60^o = 6\\
P = \frac{6}{sin60^o}\\
=\frac{6}{\sqrt{\frac{3}{2}}}=4\sqrt{3}\)
32.

If \(P = \sqrt{QR\left(1+\frac{3t}{R}\right)}\), make R the subject of the formula.

A. \(R = \frac{3Qt}{P^2 - Q}\)

B. \(R = \frac{P^2 – 3t}{Q+1}\)

C. \(R = \frac{P^2 + 3t}{Q - 1}\)

D. \(R = \frac{P^2-3Qt}{Q}\)

D

33.

From the Venn diagram below, how many elements are in P∩Q?

A. 1

B. 2

C. 4

D. 6

Detailed Solution

P \(\cap\) Q = {f, e} = 2
34.

From the Venn Diagram below, find Q' ∩ R.

A. (e)

B. (c, h)

C. (c, g, h)

D. (c, e, g, h)

Detailed Solution

Q' ∩ R
Q' = U - Q
Q' = {a, b, c, d, g, h, i}
R = {c, e, h, g}
Q' ∩ R = {c, h, g}
35.

The square root of a number is 2k. What is half of the number

A. \(\sqrt{\frac{k}{2}}\)

B. \(\sqrt{k}\)

C. \(\frac{1}{2}k^2\)

D. 2k2

Detailed Solution

Let the number be x.
\(\sqrt{x} = 2k \implies x = (2k)^2\)
= \(4k^2\)
\(\frac{1}{2} \times 4k^2 = 2k^2\)
36.

Given that p varies as the square of q and q varies inversely as the square root of r. How does p vary with r?

A. p varies as the square of r

B. p varies as the square root of r

C. p varies inversely as the square of r

D. p varies inversely as r

Detailed Solution

\(p \propto q^2\)
\(q \propto \frac{1}{\sqrt{r}\)
\(p = kq^2\)
\(q = \frac{c}{\sqrt{r}}\)
where c and k are constants.
\(q^2 = \frac{c^2}{r}\)
\(p = \frac{kc^2}{r}\)
If k and c are constants, then kc\(^2\) is also a constant, say z.
\(p = \frac{z}{r}\)
p varies inversely as r.
37.

The probabilities of a boy passing English and Mathematics test are x and y respectively. Find the probability of the boy failing both tests

A. 1-(x-y)+xy

B. 1-(x+y)-xy

C. 1-(x+y)+xy

D. 1 - (x - y) + x

Detailed Solution

Prob (passing English) = x
Prob (passing Maths) = Y
Prob (failing English) = 1 - x
Prob (failing Maths) = 1 - y
Prob (failing both test) = Prob(failing English) and Prob(failing Maths) = (1 - x)(1 - y)
=1 - y - x + xy
=1 - (y + x) + xy
38.

The locus of points equidistant from two intersecting straight lines PQ and PR is

A. a circle centre P radius Q.

B. a circle centre P radius PR

C. the point of intersection of the perpendicular bisectors of PQ and PR

D. the bisector of angle QPR

C

39.

Find the equation whose roots are \(-\frac{2}{3}\) and 3

A. 3x2+11x-6=0

B. 3x2+7x+6=0

C. 3x2-11x-6=0

D. 3x2-7x-6=0

Detailed Solution

\(x = -\frac{2}{3} \implies x + \frac{2}{3} = 0\)
\(x = 3 \implies x - 3 = 0\)
\(\implies (x - 3)(x + \frac{2}{3}) = 0\)
\(x^2 - 3x + \frac{2}{3}x - 2 = 0\)
\(x^2 - \frac{7}{3}x - 2 = 0\)
\(3x^2 - 7x - 6 = 0\)
40.

Evaluate Cos 45o Cos 30o - Sin 45o Sin 30o leaving the answer in surd form

A. \(\frac{\sqrt{2}-1}{2}\)

B. \(\frac{\sqrt{3}-\sqrt{2}}{4}\)

C. \(\frac{\sqrt{6}-\sqrt{2}}{2}\)

D. \(\frac{\sqrt{6}-\sqrt{2}}{4}\)

Detailed Solution

\(cos45^o \times cos30^o - sin45^o \times sin30^o\\
\frac{1}{\sqrt{2}}\times \frac{\sqrt{3}}{2} - \frac{1}{\sqrt{2}}\times \frac{1}{2}\\
\frac{\sqrt{3}}{2\sqrt{2}}-\frac{1}{2\sqrt{2}}; = \frac{\sqrt{3}-1}{2\sqrt{2}}=\frac{\sqrt{6}-\sqrt{2}}{4}\)
31.

In a ∆ XYZ, /YZ/ = 6cm YXZ = 60o and XYZ is a right angle. Calculate /XZ/in cm, leaving your answer in surd form

A. 2√3

B. 4√3

C. 6√3

D. 12√3

Detailed Solution

\(sin \theta = \frac{opp}{hyp}\\
sin 60^o = \frac{|YZ|}{|XZ|}=\frac{6}{P}\\
P sin 60^o = 6\\
P = \frac{6}{sin60^o}\\
=\frac{6}{\sqrt{\frac{3}{2}}}=4\sqrt{3}\)
32.

If \(P = \sqrt{QR\left(1+\frac{3t}{R}\right)}\), make R the subject of the formula.

A. \(R = \frac{3Qt}{P^2 - Q}\)

B. \(R = \frac{P^2 – 3t}{Q+1}\)

C. \(R = \frac{P^2 + 3t}{Q - 1}\)

D. \(R = \frac{P^2-3Qt}{Q}\)

D

33.

From the Venn diagram below, how many elements are in P∩Q?

A. 1

B. 2

C. 4

D. 6

Detailed Solution

P \(\cap\) Q = {f, e} = 2
34.

From the Venn Diagram below, find Q' ∩ R.

A. (e)

B. (c, h)

C. (c, g, h)

D. (c, e, g, h)

Detailed Solution

Q' ∩ R
Q' = U - Q
Q' = {a, b, c, d, g, h, i}
R = {c, e, h, g}
Q' ∩ R = {c, h, g}
35.

The square root of a number is 2k. What is half of the number

A. \(\sqrt{\frac{k}{2}}\)

B. \(\sqrt{k}\)

C. \(\frac{1}{2}k^2\)

D. 2k2

Detailed Solution

Let the number be x.
\(\sqrt{x} = 2k \implies x = (2k)^2\)
= \(4k^2\)
\(\frac{1}{2} \times 4k^2 = 2k^2\)
36.

Given that p varies as the square of q and q varies inversely as the square root of r. How does p vary with r?

A. p varies as the square of r

B. p varies as the square root of r

C. p varies inversely as the square of r

D. p varies inversely as r

Detailed Solution

\(p \propto q^2\)
\(q \propto \frac{1}{\sqrt{r}\)
\(p = kq^2\)
\(q = \frac{c}{\sqrt{r}}\)
where c and k are constants.
\(q^2 = \frac{c^2}{r}\)
\(p = \frac{kc^2}{r}\)
If k and c are constants, then kc\(^2\) is also a constant, say z.
\(p = \frac{z}{r}\)
p varies inversely as r.
37.

The probabilities of a boy passing English and Mathematics test are x and y respectively. Find the probability of the boy failing both tests

A. 1-(x-y)+xy

B. 1-(x+y)-xy

C. 1-(x+y)+xy

D. 1 - (x - y) + x

Detailed Solution

Prob (passing English) = x
Prob (passing Maths) = Y
Prob (failing English) = 1 - x
Prob (failing Maths) = 1 - y
Prob (failing both test) = Prob(failing English) and Prob(failing Maths) = (1 - x)(1 - y)
=1 - y - x + xy
=1 - (y + x) + xy
38.

The locus of points equidistant from two intersecting straight lines PQ and PR is

A. a circle centre P radius Q.

B. a circle centre P radius PR

C. the point of intersection of the perpendicular bisectors of PQ and PR

D. the bisector of angle QPR

C

39.

Find the equation whose roots are \(-\frac{2}{3}\) and 3

A. 3x2+11x-6=0

B. 3x2+7x+6=0

C. 3x2-11x-6=0

D. 3x2-7x-6=0

Detailed Solution

\(x = -\frac{2}{3} \implies x + \frac{2}{3} = 0\)
\(x = 3 \implies x - 3 = 0\)
\(\implies (x - 3)(x + \frac{2}{3}) = 0\)
\(x^2 - 3x + \frac{2}{3}x - 2 = 0\)
\(x^2 - \frac{7}{3}x - 2 = 0\)
\(3x^2 - 7x - 6 = 0\)
40.

Evaluate Cos 45o Cos 30o - Sin 45o Sin 30o leaving the answer in surd form

A. \(\frac{\sqrt{2}-1}{2}\)

B. \(\frac{\sqrt{3}-\sqrt{2}}{4}\)

C. \(\frac{\sqrt{6}-\sqrt{2}}{2}\)

D. \(\frac{\sqrt{6}-\sqrt{2}}{4}\)

Detailed Solution

\(cos45^o \times cos30^o - sin45^o \times sin30^o\\
\frac{1}{\sqrt{2}}\times \frac{\sqrt{3}}{2} - \frac{1}{\sqrt{2}}\times \frac{1}{2}\\
\frac{\sqrt{3}}{2\sqrt{2}}-\frac{1}{2\sqrt{2}}; = \frac{\sqrt{3}-1}{2\sqrt{2}}=\frac{\sqrt{6}-\sqrt{2}}{4}\)