NECO Mathematics Past Questions & Answers - Page 23

111.

The nth term of a sequence is given as \(4 \times 3^{(3 - n)}\). Calculate the third term.

A.

12

B.

32

C.

4

D.

3

E.

1

Correct answer is C

\(4 \times 3^{(3 - n)}\)

for the third term, n = 3

then 

\(4 \times 3^{(3 - 3)}\) = \(4 \times 3^{0}\) = 4 x 1 = 4.

 

112.

Two angles of a triangle are 45º each and its longest side is 12cm. Find the length of one of the other sides

A.

12cm

B.

9\(\sqrt{2}\)cm

C.

6\(\sqrt{2}\)cm

D.

6cm

E.

3\(\sqrt{2}\)cm

Correct answer is C

Two angles of a triangle are 45º each and its longest side is 12cm, this simply describes an isosceles triangle

two equal angles and two equal sides

using Pythagoras theorem,

\(x^2 + x^2 = 12^2\)

 \(2x^2\) = 144

\(x^2\) = 72( after dividing b/sides by 2)

x = \(\sqrt{72} = 6\sqrt{2}\)cm.

113.

Find the surface area of a sphere whose radius is 3.5cm, correct your answer to one decimal place (π = \(\frac{22}{5}\))

A.

12.8cm2

B.

25.7cm2

C.

77.0cm2

D.

154.0cm2

E.

179.7cm2

Correct answer is D

No explanation has been provided for this answer.

114.

The length, breadth and height of a cuboid are 8cm, 7\(\frac{1}{2}\)cm and 6\(\frac{1}{2}\) cm respectively. What Is its volume in m3 (leave your answer in standard form)?

A.

3.9 × 10-1m3

B.

3.9 × 10-2m3

C.

3.9 × 10-3m3

D.

3.9 × 10-4m3

E.

3.9 × 10-5m3

Correct answer is D

No explanation has been provided for this answer.