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JAMB Mathematics Past Questions & Answers - Page 20

96.

The equivalent of (10110.011)2 in base 10 is?

A.

26.325

B.

24.372

C.

42.443

D.

22.375

Correct answer is D

Using the expansion method on (10110.011)2

(1 * 24) + (0 * 23) + (1 * 22) + (1 * 21) (0 * 20) + (0 * 21) + (1 * 22)  + (1 * 23)

(1*16) + 0 (1*4) + (1*2) + 0 + 0 + (1*14) + (1*18

16 + 4 + 2 + (0.25 + 0.125)

22 + 0.375

(10110.011)2 = 22.37510

97.

Calculate the median of 14, 17, 10, 13, 18 and 10.

A.

12.5

B.

13.5

C.

13.2

D.

14.5

Correct answer is B

When rearranged: 10, 10, 13, 14, 17, 18

median = 13+142

= 272 or 13.5

98.

Find the equation of a straight line parallel to the line 2x - y = 5 and having intercept of 5

A.

2x + y = 5

B.

2x + y = -5

C.

2x - y = -5

D.

2x - y = 5

Correct answer is C

Condition for Parallelism means that their gradient value is same

line 2x - y = 5 is rearranged

As y = 2x - 5 from y = mx + c

: line 2x - y = 5 has the gradient of 2

A parallel line with gradient of 2 and intercept of 5

→ 2x - y = -5

Rearranged as y = 2x + 5

99.

Find the limit of y = x3+6x7x1 as x tends to 1

A.

9

B.

8

C.

0

D.

7

Correct answer is A

x3+6x7x1:

When numerator is differentiated → 3x2 + 6  

When denominator is differentiated → 1

3x2+61

substitute x for 1

 312+61 =  3+61 

=  91

= 9

100.

If sec2θ + tan2θ = 3, then the angle θ is equal to?

A.

90º

B.

30º

C.

45º

D.

60º

Correct answer is C

Given that sec2θ + tan2θ = 3

Where sec2θ = 1  + tan2θ

: 1 + tan2θ + tan2θ = 3

2tan2θ = 3 - 1

2tan2θ = 2

divide both sides by 2

tan2θ = 1

tanθ =  √1

tanθ = 1

θ = tan1 (1)

θ = 45º