JAMB Mathematics Past Questions & Answers - Page 139

691.

In the figure, PQR is a straight line. Find the values of x and y

x = 22.5^o, y = 33.75^o

x = 15^o, y = 52.5^o

x = 22.5^o, y = 45.0^o

x = 56.25^o, y = 11.5^o

View answer & explanation

Correct answer is A

\(\frac{3}{2}\)x + 3y + 45° = 180°

3x + 6y + 90° = 360°

3x + 6y = 270.......(i) x 2,

5x + y + y = 180°

5x + 2y = 180° ... (ii) x 6

6x + 12y = 540 ... (iii)

30x + 12y = 1080 ... (iv)

eqn(iv) - eqn(iii)

24x = 540

x = 22.5° and y = 33.75°

692.

The farm yield of four crops on a piece of land in Ondo are represented on the pie chart. what is the angle of the sector occupies by Okro in the chart?

11^o

19\(\frac{1}{3}\)^o

33\(\frac{1}{3}\)^o

91\(\frac{1}{3}\)^o

91^o

View answer & explanation

Correct answer is B

Adding the values of all the items together, it gives 70

Okro sector = \(\frac{145}{270}\) x \(\frac{360^o}{1}\)

= 19.33^o

= 19\(\frac{1}{3}\)^o

693.

PQRS isa cyclic quadrilateral which PQ = PS. PT is a tangent to the circle and PQ makes an angle of 50o with the tangent as shown in the figure. What is the size of QRS?

50^o

40^o

110^o

80^o

100^o

View answer & explanation

Correct answer is E

< SPQ = 80o

< SPQ + < SRQ = 180(Supplementary)

80 +
< QRS = 180o - 80o

= 100o

694.

If O is the centre of the circle in the figure, find the value of x

260

100

130

View answer & explanation

Correct answer is C

From the diagram; The value of x = 360^o - 2(130^o)

= 360 - 260

= 100^o

695.

PQRS is a desk of dimensions 2m x 0.8 which is inclined at 30o to the horizontal. Find the inclination of the diagonal PR to the horizontal

30^o 35'

30^o 32'

15^o 36'

10^o

10^o 42'

View answer & explanation

Correct answer is E

tan\(\theta\) = \(\frac{0.8}{2}\) = (0.4)

\(\theta\) = tan^-1(0.4)

From the diagram, the inclination of the diagonal PR to the horizontal is 10^o 42'