NECO Past Questions and Answers - Page 149

741.

Express 0.03785 in standard form correct to 3 significant figures.

A.

3 × 10\(^{-2}\)

B.

3.78 × 10\(^{-2}\)

C.

3.79 × 10\(^{-2}\)

D.

3.79 × 10\(^{-1}\)

E.

3.78 × 10\(^{-2}\)

Correct answer is C

No explanation has been provided for this answer.

742.

The first term of a G.P is 7. Find its 4th term, if its common ratio is 3.

A.

567

B.

280

C.

189

D.

63

E.

21

Correct answer is C

No explanation has been provided for this answer.

743.

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.

744.

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

745.

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 

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

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