Year : 
1990
Title : 
Mathematics (Core)
Exam : 
JAMB Exam

Paper 1 | Objectives

41 - 44 of 44 Questions

# Question Ans
41.

In triangles XYZ and XQP, XP = 4cm, XQ = 5cm and PQ = QY = 3cm. Find ZY

A. 8cm

B. 6cm

C. 4cm

D. 3cm

B

42.

In the figure, YXZ = 30o, XYZ = 105o and XY = 8cm. Calculate YZ

A. 16\(\sqrt{2}\)cm

B. 8\(\sqrt{2}\)cm

C. 4\(\sqrt{2}\)cm

D. 22cm

Detailed Solution

yzx + 105o + 30o = 180o

yzx = 180 - 155 = 45o

\(\frac{yz}{sin 30^o} = \frac{8}{sin 45^o}\)

yz = \(\frac{8 \sin 30}{sin 45}\)

= 8(\(\frac{1}{2}) = \frac{8}{1} \times \frac{1}{2} \times \frac{\sqrt{2}}{1}\)

= 4 \(\div\) \(\frac{1}{\sqrt{2}}\)

= 4\(\sqrt{2}\)cm
43.

In the figure, PQR is a semicircle. Calculate the area of the shaded region

A. 125\(\frac{2}{7}\)2

B. 149\(\frac{2}{7}\)cm2

C. 234\(\frac{1}{7}\)cm2

D. 267\(\frac{1}{2}\)cm2

A

44.

Find the curved surface area of the frustrum in the figure

A. 16\(\pi \sqrt{10}\)cm2

B. 20\(\pi \sqrt{10}\)cm2

C. 24\(\pi \sqrt{10}\)cm2

D. 36\(\pi \sqrt{10}\)cm2

Detailed Solution

\(\frac{x}{4} = \frac{6 + x}{6}\)

6x = 4(6 + x) = 24 + 4x

x = 12cm
CSA = \(\pi RL - \pi rl\)

= \(\pi (6) \sqrt{{18^2} + 6^2} - \pi \times 4 \times \sqrt{{12^2} + 4^2}\)

= 6\(\pi \sqrt{360} - 4 \pi \sqrt{160}\)

= 36\(\pi \sqrt{10} - 16 \pi \sqrt{10}\)

= 20\(\pi \sqrt{10}\)cm2
41.

In triangles XYZ and XQP, XP = 4cm, XQ = 5cm and PQ = QY = 3cm. Find ZY

A. 8cm

B. 6cm

C. 4cm

D. 3cm

B

42.

In the figure, YXZ = 30o, XYZ = 105o and XY = 8cm. Calculate YZ

A. 16\(\sqrt{2}\)cm

B. 8\(\sqrt{2}\)cm

C. 4\(\sqrt{2}\)cm

D. 22cm

Detailed Solution

yzx + 105o + 30o = 180o

yzx = 180 - 155 = 45o

\(\frac{yz}{sin 30^o} = \frac{8}{sin 45^o}\)

yz = \(\frac{8 \sin 30}{sin 45}\)

= 8(\(\frac{1}{2}) = \frac{8}{1} \times \frac{1}{2} \times \frac{\sqrt{2}}{1}\)

= 4 \(\div\) \(\frac{1}{\sqrt{2}}\)

= 4\(\sqrt{2}\)cm
43.

In the figure, PQR is a semicircle. Calculate the area of the shaded region

A. 125\(\frac{2}{7}\)2

B. 149\(\frac{2}{7}\)cm2

C. 234\(\frac{1}{7}\)cm2

D. 267\(\frac{1}{2}\)cm2

A

44.

Find the curved surface area of the frustrum in the figure

A. 16\(\pi \sqrt{10}\)cm2

B. 20\(\pi \sqrt{10}\)cm2

C. 24\(\pi \sqrt{10}\)cm2

D. 36\(\pi \sqrt{10}\)cm2

Detailed Solution

\(\frac{x}{4} = \frac{6 + x}{6}\)

6x = 4(6 + x) = 24 + 4x

x = 12cm
CSA = \(\pi RL - \pi rl\)

= \(\pi (6) \sqrt{{18^2} + 6^2} - \pi \times 4 \times \sqrt{{12^2} + 4^2}\)

= 6\(\pi \sqrt{360} - 4 \pi \sqrt{160}\)

= 36\(\pi \sqrt{10} - 16 \pi \sqrt{10}\)

= 20\(\pi \sqrt{10}\)cm2