NECO Past Questions and Answers - Page 155

771.

The angle of elevation of the top T of a pole from a point X on the horizontal ground is 32°, if X is 68 m away from the foot F of the pole, calculate the height FT of the pole, correct to one decimal place.

A.

128.3m

B.

108.8m

C.

80.2m

D.

57.7m

E.

42.5m

Correct answer is E

to calculate for the high of the pole, we use sohcahtoa

Let the height of the pole be x.

Tan32º = \(\frac{opp}{adj}\)

Tan32º =  \(\frac{x}{68}\)

x = Tan32º x 68 = 42.5m ( to 1 d.p)

772.

Find the value of k such that \(t^2\) + kt + \(\frac{25}{4}\) is a perfect square

A.

5

B.

3

C.

\(\frac{5}{2}\)

D.

\(\frac{5}{4}\)

E.

\(\frac{1}{5}\)

Correct answer is A

No explanation has been provided for this answer.

773.

If 3 boys shared x oranges among themselves in the ratio 3:5:8, and smallest share was 45 oranges, find the value of x

A.

75

B.

120

C.

165

D.

195

E.

240

Correct answer is E

No explanation has been provided for this answer.

774.

If n{A} = 6, n{B} = 5 and n{A ∩ B} = 2, find n{A ∪ B}

A.

7

B.

8

C.

9

D.

13

E.

15

Correct answer is C

No explanation has been provided for this answer.

775.

An arc of a circle subtends an angle of 75° at the centre of the circle. If the diameter of the circle is 7cm, what Is the length of the arc? (take π = 3.142)

A.

4.58 cm

B.

8.02 cm

C.

16.04 cm

D.

32.08 cm

E.

34 cm

Correct answer is A

No explanation has been provided for this answer.