NECO Mathematics Past Questions & Answers - Page 32

156.

A trader sold an article for N4,600.00 thereby making a profit of 15%. Calculate the cost price of the article

A.

N3450.00

B.

N3910.00

C.

N4000.00

D.

N5290.00

E.

N6900.00

Correct answer is C

No explanation has been provided for this answer.

157.

The radius of a sphere is 21cm. If s and v represent the curved surface area and volume respectively, what is s : v? (take π = 3.142)

A.

1:03

B.

1:07

C.

3:01

D.

3:07

E.

7:01

Correct answer is B

C.S.A = 5,544 Volume = 38,808 S : V = 1 : 07

158.

51 women wore coloured shoes to a party, out of which 21 wore purple and 9 wore white. if a woman is selected at Random. What is the probability that she is wearing neither a purple shoe nor a white shoe?

A.

\(\frac{10}{17}\)

B.

\(\frac{7}{17}\)

C.

\(\frac{20}{51}\)

D.

\(\frac{3}{17}\)

E.

\(\frac{1}{51}\)

Correct answer is B

No of women wearing both purple and white shoes = 21 + 9

= 30 women.

No of women wearing neither purple nor white shoes = 51 - 30

= 21 women

\(\therefore\) Probability of picking a woman wearing neither purple nor white shoes 

= \(\frac{21}{51}\)

= \(\frac{7}{17}\).

159.

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

\(r = 7m\)

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

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

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

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

160.

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.