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JAMB Mathematics Past Questions & Answers - Page 137

681.

The diagram is the distance time graph of a vehicle. Find its average speed in kilometers per hour during the journey

A.

155km/hr

B.

50km/hr

C.

40km/hr

D.

124km/hr

E.

84km/hr

Correct answer is E

Distance = 155 - 50 = 105km

Time = 75mins

= 7560hr = 54hr

Average speed = Distancetime = 10554

= 105×45

= 84km\h

682.

In the diagram, angle QPR = 90o, angle PSR = 90o and PR = 5 units. Find the length of QS.

A.

5 tan 25o sin 65o

B.

5 cos 25o sin 65o

C.

5 tan 25o cos 65o

D.

cos 25o cos 65o

E.

5 cosec 25o

Correct answer is C

From QPR, < R = 180o - (25o + 90o)

180o - 115o = 65o

From PSQ, Sin 65o = QPRhyp = PS5

PS = 5 sin 65o

From PSR, tan = OPPadj = PSQS

but PS = 5 sin 65o

QS tan 25o = PS

QS tan 25o = 5 sin 65o

QS = 5sin65otan25o

= 5 tan 25o cos 65o

683.

In the figure, WU//YZ, WY//YZ = 12cm, VZ = 6cm, XU = 8cm. Determine the length of WU.

A.

1cm``3cm

B.

6cm

C.

2cm

D.

4cm

Correct answer is D

From similar triangle, x6 = 812

12x = 48

x = 4812

= 4

684.

In the diagram, XZ is the diameter of a circle's radius 52. If XY is 4cm, then the area of the triangle XYZ is

A.

12cm2

B.

2812cm2

C.

16cm2

D.

10cm2

E.

6cm2

Correct answer is E

Area of the triangle XYZ = 12bh = 12ZY x XY

= 12 x 3 x 4

= 6cm2.

685.

In the figure, find x in terms of a, b and c.

A.

a + b + c

B.

180o - (a + b + c)

C.

a - b - c

D.

a + b

E.

a + c

Correct answer is A

180 - x + a + b + c

= 180(sum of interior angle in triangle)

a + b + c = x.