NECO Past Questions and Answers - Page 150

746.

The surface area of a sphere is 616m2. what is the volume of-the sphere (correct to two significant figures)? (take π = 3.142)

A.

14 cm\(^3\)

B.

210 cm\(^3\)

C.

1,400 cm\(^3\)

D.

2,100 cm\(^3\)

E.

4,300 cm\(^3\)

Correct answer is C

\(Surface area (A) = 4\pi r^{2} = 616m^{2}\)

solving, we have

\(r = 7m\)

\(Volume = \frac{4}{3}\pi r^{3}\)

\(Volume = \frac{4\times 3.142 \times 7^{3}}{3}\)

\(Volume = \frac{4310.824}{3}\)

= \(1436.941m^{3} \approxeq 1400m^{3}(2 sig. fig)\)

747.

In an acute angle-triangle XYZ, XZ = 9cm, YZ = 11cm and ∠XZY = 35° Calculate ∠YXZ, correct to the nearest degree.

A.

57°

B.

45°

C.

33°

D.

16°

E.

89°

Correct answer is B

No explanation has been provided for this answer.

748.

Find the value of x in the equation: 9x = 729

A.

81

B.

27

C.

18

D.

9

E.

3

Correct answer is A

No explanation has been provided for this answer.

749.

Simplify \(\sqrt{6a} \times \sqrt{576a^6}\)

A.

± 16a2

B.

± 16a

C.

± 14a2

D.

± 12a2

E.

± 12a

Correct answer is D

No explanation has been provided for this answer.

750.

Two beads are drawn at random, one after the other, with replacement, from a box containing 5 red and 7 white identical beads. What is the probability that the beads are the same colour

A.

\(\frac{119}{144}\)

B.

\(\frac{95}{144}\)

C.

\(\frac{37}{72}\)

D.

\(\frac{49}{144}\)

E.

\(\frac{1}{6}\)

Correct answer is C

No explanation has been provided for this answer.