NECO Past Questions and Answers - Page 130

646.

What is the Value of 11101\(_{two}\)+ 10011\(_{two}\) - 10001\(_{two}\)?

A.

10001\(_{two}\)

B.

10011\(_{two}\)

C.

10111\(_{two}\)

D.

11111\(_{two}\)

E.

111111\(_{two}\)

Correct answer is D

11101\(_{two}\) →      29

+ 10011\(_{two}\)  → 19

- 10001\(_{two}\)  → 17

 11111 = 31

647.

Evaluate 0.0025 × 2.5 × 102 to 2 significant figures.

A.

0.625 × 10-3

B.

0.63 × 10-2

C.

6.25 × 10-3

D.

6.3 × 10-2

E.

6.3 × 10-1

Correct answer is E

No explanation has been provided for this answer.

648.

If x + \(\frac{1}{x}\) = 8, find x2 + \(\frac{1}{x^2}\)

A.

64

B.

62

C.

32

D.

16

E.

4

Correct answer is B

No explanation has been provided for this answer.

649.

A surveyor measured the length of a obtained 42.55 metres. If his measurement was more than the actual length and the percentage error of his measurement was 8%, calculate the actual length of the land

A.

39.40 metres

B.

46.20 metres

C.

46.25 metres

D.

46.50 metres

E.

48.25 metres

Correct answer is A

No explanation has been provided for this answer.

650.

Solve for x in the quadratic equation. 2x2 + 12x + 10 = 0

A.

x = -5, -1

B.

x = -5,1

C.

x = -3, -2

D.

x = 3, 2

E.

x = 6, 5

Correct answer is A

No explanation has been provided for this answer.