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JAMB Mathematics Past Questions & Answers - Page 151

751.

Arrange 35,916, 3459 and 7197 in ascending order of magnitude.

A.

35, 916, 3459, 7197

B.

916, 3459, 35 , 7197

C.

35, 916, 7197, 3459

D.

916, 35, 7197, 3459

Correct answer is B

35 = 0.60, 916 = 0.56, 3459 = 0.58, 7197 = 0.73

Hence, 916<3459<35<7197

752.

Multiply (x + 3y + 5) by (2x2 + 5y + 2)

A.

2x2 + 3yx2 + 10xy + 15y2 + 13y + 10x2 + 2x + 10

B.

2x3 + 6yx2 + 5xy + 15y2 + 31y + 5x2 + 2x + 10

C.

2x3 + 6xy2 + 5xy + 15y2 + 12y + 10x2 + 2x = 10

D.

2x2 + 6xy2 + 5xy + 15y2 + 13y + 10x2 + 2x + 10

E.

2x3 + 2yx2 + 10xy + 10y2 + 31y + 5x2 + 10

Correct answer is B

(x+3y+5)(2x2+5y+2)

= 2x3+5xy+2x+6yx2+15y2+6y+10x2+25y+10

= 2x3+5xy+2x+6yx2+15y2+31y+10x2+10

753.

The sum of 378 and 113 is less than the difference between 18 and 123 by:

A.

323

B.

514

C.

612

D.

8

E.

818

Correct answer is A

378+113=421+824

= 42924

5524

12318=5318

= 40324

= 3724

55243724=125243724

= 8824

= 323

754.

A rectangular picture 6cm by 8cm is enclosed by a frame 12cm wide. Calculate the area of the frame

A.

15sq.cm

B.

20sq.cm

C.

13sq.cm

D.

16sq.cm

E.

17sq.cm

Correct answer is A

Area of the rectangular picture = L x B = 8 x 6

= 48 sq.cm.

Area of the whole surface (which is gotten by adding 12 on every side to the original picture size) is 9 x 7 = 63 sq. cm

area of the frame is 63 - 48

= 15 sq. cm

755.

A man is standing in the corridor of a 10-storey building and looking down at a tall tree in front of the building. He sees the top of the tree at angle of depression of 30o. If the tree is 200m tall and the man's eyes are 300m above the ground, calculate the angle of depression of the foot tree as seen by the man

A.

30o

B.

60o

C.

45o

D.

25o

Correct answer is B

Let x rep. the angle of depression of the foot of the tree.

tan 30o = y100

y = 100 tan 30o

= 57.8

By Pythagoras, AC2 = 3002 + 582

= 900 + 3354

tan x = oppadj

= 58300

= 0.19

tan x = 0.19

x = tan 0.19

= 60o