Processing math: 92%

JAMB Mathematics Past Questions & Answers - Page 105

521.

Find the value of x in the figure above

20 $\sqrt{3}$ cm

10 $\sqrt{3}$ cm

5 $\sqrt{3}$ cm

4 $\sqrt{3}$ cm

View answer & explanation

Correct answer is B

In the figure above, $\frac{x}{\sin 60^o} = \frac{10}{\sin 30^o}$ (Sine rule)

x = $\frac{10 \sin 60^o}{\sin 30^o}$

= 10 x $\frac{\sqrt{3}}{2} \times \frac{1}{2}$

= 10 x $\frac{\sqrt{3}}{2} \times \frac{2}{1}$

= 10 $\sqrt{3}$ cm

522.

From the figure above, what is the value of p?

135^o

90^o

60^o

45^o

View answer & explanation

Correct answer is B

In the figure above, q^o = 30^o (vertically opposite angles)

(P + 2q)^o + 30^o = 180^o(angles on a straight line)

p + 2 x 30^o + 30^o = 180^o

p + 60^o + 30^o = 180^o

p + 90^o = 180^o

p = 180^o - 90^o

= 90^o

523.

In the figure above, KL//NM, LN bisects < KNM. If angles KLN is 54^o and angle MKN is 35^o, calculate the size of angle KMN.

91^o

89^o

37^o

19^o

View answer & explanation

Correct answer is C

In the diagram above, $\alpha$ = 54^o(alternate angles; KL||MN) < KNM = 2 $\alpha$ (LN is bisector of < KNM) = 108^o

35^o + < KMN + 108^o = 180^o(sum of angles of $\bigtriangleup$ )

< KMN + 143^o = 180^o

< KMN = 180^o - 143^o

= 37^o

524.

From the venn diagram above, the shaded parts represent

(P $\cap$ Q) $\cup$ (P $\cap$ R)

(P $\cup$ Q) $\cap$ (P $\cap$ R)

(P $\cup$ Q) $\cup$ (P $\cup$ R)

(P $\cap$ Q) $\cup$ (P $\cup$ R)

View answer & explanation

Correct answer is A

No explanation has been provided for this answer.

525.

The pie chart above shows the statistical distribution of 80 students in five subjects in an examination. Calculate how many student offer Mathematics.

View answer & explanation

Correct answer is B

5x° + (16x - 24)° + 5x° + (4x + 12)° + (6x + 12)° = 360°

36x° - 24 + 12 + 12 = 360°

36x° = 360°

x° = $\frac{360°}{36}$

= 10°

Thus, the angle of sector representing Mathematics is 5 x 10° = 50°. Hence the number of students who offer mathematics is

$\frac{50}{360} \times 80 \approx 11$