JAMB Mathematics Past Questions & Answers - Page 143

711.

In the figure, the chords XY and ZW are produced to meet at T such that YT = WT, ZYW = 40o and YTW = 30o. What is YXW?

A.

50o

B.

75o

C.

35o

D.

115o

E.

30o

Correct answer is C

< WYT = \(\frac{180 - 30}{2}\)

= \(\frac{150}{2}\)

= 75o(base angles of isosceles D)

YXW = 75 - 40 = 35o(Exterior angle is equal to sum of interior angles)

712.

Find the area of the shades segments in the figure

A.

\(\sqrt{3}\)

B.

4 \(\pi - \sqrt{3}\)

C.

-\(\frac{2}{3} \pi\)

D.

\(\frac{2\pi}{3}\) -3

Correct answer is D

Area of section = \(\frac{60^o}{360^o}\) x 11r2

= \(\frac{60}{360} \times \pi \times 2^2\)

= \(\frac{1}{6}\) x 4

= \(\frac{4\pi}{6}\)

= \(\frac{2\pi}{3}\)

Area of triangle = \(\frac{1}{2x}\)

= 2 x 28.......60

Segment Area = Area of section - Area of triangle

= \(\frac{2\pi}{3}\) -3

713.

If \(\theta\) = \(\frac{3}{2}\) and \(\theta\) is less than 90o, calculate tan \(\frac{(90 - \theta)}{cos^2\theta}\)

A.

\(\frac{1}{2}\)

B.

\(\frac{4}{\sqrt{3}}\)

C.

\(\sqrt{3}\)

D.

4\(\sqrt{3}\)

Correct answer is B

No explanation has been provided for this answer.

714.

In the figure, PS = SR and Rx is a tangent to the circle at R, < QRX is equal to 72o.  Find angle SPR

A.

20o

B.

36o

C.

72o

D.

30o

E.

15o

Correct answer is B

XRQ = RSQ (Alternate segment)

s = 72o

(80o - 72o = 180o)

a + b + c = 190o = 2b + c = 180o

2b + 108 = 180o

2b = 72o

b = 36o

715.

The angles marked in the figure are measured in degrees. Find x.

A.

45o

B.

90o

C.

60o

D.

15o

E.

30o

Correct answer is E

Sum of external angles = 360o

3x + 5x + x + 2x + x = 360o

12x = 360o

x = 30o