Mathematics questions and answers

Mathematics Questions and Answers

How good are you with figures and formulas? Find out with these Mathematics past questions and answers. This Test is useful for both job aptitude test candidates and students preparing for JAMB, WAEC, NECO or Post UTME.

1,881.

Find, correct to three significant figures, the value of \(\sqrt{41830}\).

A.

205

B.

647

C.

2050

D.

6470

E.

64.7

Correct answer is A

\(\sqrt{41830} = 204.5238\)

\(\approxeq 205\) (to three significant figures)

1,882.

What is the length of an arc of a circle that substends 2\(\frac{1}{2}\) radians at the centre when the raduis of the circle = \(\frac{k}{k + 1}\) + \(\frac{k + 1}{k}\) then

A.

p< 0

B.

p\(\geq\) 0

C.

p \(\leq\) 0

D.

p < 1

E.

p > 0

Correct answer is E

\(\frac{k}{k + 1}\) + \(\frac{k + 1}{k}\)

= \(\frac{k^2 + (k + 1)^2}{k(k + 10}\)

= \(\frac{2k^2 + 2k + 1}{k(k + 1}\)

let k = \(\frac{1}{2}\)

p = \(\frac{10}{3}\)

p > 0

1,883.

Solve the given equation \((\log_{3} x)^{2} - 6(\log_{3} x) + 9 = 0\)

A.

27

B.

9

C.

\(\frac{1}{27}\)

D.

18

E.

81

Correct answer is A

\((\log_{3} x)^{2} - 6(\log_{3} x) + 9 = 0\)

Let \(\log_{3} x = a\).

\(a^{2} - 6a + 9 = 0\)

\(a^{2} - 3a - 3a + 9 = 0\)

\(a(a - 3) - 3(a - 3) = 0\)

\((a - 3)(a - 3) = 0\)

\(\implies a = 3 (twice)\)

\(\log_{3} x = 3 \implies x = 3^{3} = 27\)

1,884.

The sum of the root of a quadratic equation is \(\frac{5}{2}\) and the product of its root is 4. The quadratic equation is

A.

x + 8x2 - 5 = 0

B.

2x2 - 5x + 8 = 0

C.

2x2 - 8x + 5 = 0

D.

x2 + 8x - 5 = 0

Correct answer is B

x2 - (sum of roots) x + (product of roots) = 0

x2 - \(\frac{5x}{2}\) + 4 = 0

2x2 - 5x + 8 = 0

1,885.

What is the size of an exterior angle of a regular pentagon?

A.

36o

B.

60o

C.

72o

D.

120o

E.

360o

Correct answer is C

Pentagon is a polygon with 5 sides. Sum of interior angles of polygon (regular) = (2n - 4) x 90o

= 5

= (10 - 4) x 90o

= 540o

each interior angle = \(\frac{540}{5}\)

= 108o

= 180o let x represent ext. angle

x + 108o = 180v

x = 180o - 108o

= 72o