JAMB Mathematics Past Questions & Answers - Page 109

541.

In diagram above, QR//TU, < PQR = 80° and < PSU = 95°. Calculate < SUT.

A.

15o

B.

25o

C.

30o

D.

80o

Correct answer is A

< PQR = < PTU = 80°

< TSU = 85°

x = 180° - (80° + 85°)

= 15°

542.

The shaded region above is represented by
the equation

A.

y ≤ 4x + 2

B.

y ≥ 4x + 2

C.

y ≤ -4x + 4

D.

y ≤ 4x + 4

Correct answer is C

Equation of the line

\(\frac{y - 4}{x - 0} = \frac{0 - 4}{1 - 0}\)

\(\frac{y - 4}{x} = \frac{-4}{1}\)

\(\therefore -4x = y - 4\)

\(y = -4x + 4\)

\(\therefore \text{The shaded portion = } y \leq -4x + 4\)

543.

The pie chart above shows the monthly distribution of a man's salary on food items. If he spent N8,000 on rice, how much did he spent on yam?

A.

N42,000

B.

N18,000

C.

N16,000

D.

N12,000

Correct answer is C

Angle of sector subtended by yam

= 360o - (70 + 80 + 50)o

= 360o - 200o

= 160o

But \(\frac{80^o}{360^o}\) x T = 8000

T = \(\frac{8000 \times 360^o}{80^o}\)

= N36,000

Hence the amount spent on yam = \(\frac{160^o}{260} \times N36,000\)

= N16,000

544.

in the figure above, what is the equation of the line that passes the y-axis at (0,5) and passes the x-axis at (5,0)?

A.

y = x + 5

B.

y = -x + 5

C.

y = x - 5

D.

y = -x - 5

Correct answer is B

(x1, y1) = (0,5)

(x2, y2) = (5, 0)

Using \(\frac{y - y_1}{y_2 - y_1} = \frac{x - x_1}{x_2 - x_1}\)

\(\frac{y - 5}{0 - 5} = \frac{x - 0}{5 - 0}\)

\(\frac{y - 5}{-5} = \frac{x}{5}\)

5(y - 5) = -5x

y - 5 = -x

x + y = 5

y = -x + 5

545.

Find the value of x in the figure above

A.

20\(\sqrt{3}\)cm

B.

10\(\sqrt{3}\)cm

C.

5\(\sqrt{3}\)cm

D.

4\(\sqrt{3}\)cm

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