NECO Past Questions and Answers - Page 145

721.

What is the total surface area of a cylinder with radius 2cm and height 1.5cm, correct to 2 significant figures?

A.

440cm\(^2\)

B.

220cm\(^2\)

C.

88cm\(^2\)

D.

44cm\(^2\)

E.

22cm\(^2\)

Correct answer is D

T.S.A of a cylinder = \(2\pi r (r + h)\)

= \(2 \times \frac{22}{7} \times 2 (2 + 1.5)\)

= 44 cm\(^2\)

722.

The probability that a student will pass a mathematics test is ⅗. If 3 students are chosen at random, what is the probability that at least 2 of them will pass the test?

A.

\(\frac{27}{125}\)

B.

\(\frac{9}{25}\)

C.

\(\frac{72}{125}\)

D.

\(\frac{76}{125}\)

E.

\(\frac{81}{125}\)

Correct answer is E

No explanation has been provided for this answer.

723.

If \(\frac{t}{1}\) = \(\sqrt{(\frac{4\pi^2}{g}})\), what is the value of g when I = 4.5; t = 5 secs

A.

3.20 ms2

B.

11.31 ms2

C.

32.00 ms2

D.

56.57 ms2

E.

160.00 ms2

Correct answer is C

No explanation has been provided for this answer.

724.

The angle of elevation of the top (T) of a palm tree from a point (R) on the ground is 30°. The distance from R to the base (B) of the palm tree is 120m. What is the distance between T and R?

A.

60m

B.

60\(\sqrt{3}\)m

C.

80\(\sqrt{3}\)m

D.

120\(\sqrt{3}\)m

E.

240m

Correct answer is C

No explanation has been provided for this answer.