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.

551.

Make x the subject of the relation d = \(\sqrt{\frac{6}{x} - \frac{y}{2}}\)

A.

x = \(\frac{6 + 12}{d^2 + y}\)

B.

x = \(\frac{12}{d^2 - y}\)

C.

x = \(\frac{12}{y} - 2d^2\)

D.

x = \(\frac{12}{2d^2 + y}\)

Correct answer is D

d = \(\sqrt{\frac{6}{x} - \frac{y}{2}}\)

\(d^2 = \frac{6}{x} - \frac{y}{2}\)

\(2xd^2 = 12 - xy\)

\(2xd^2 + xy = 12\)

x = \(\frac{12}{2d^2 + y}\)

552.

The roots of a quadratic equation are \(\frac{-1}{2}\) and \(\frac{2}{3}\). Find the equation.

A.

\(6x^2 - x + 2 = 0\)

B.

\(6x^2 - x - 2 = 0\)

C.

\(6x^2 + x - 2 = 0\)

D.

\(6x^2 + x + 2 = 0\)

Correct answer is B

(x + \(\frac{1}{2}\)) (n - \(\frac{2}{3}\))

\(x^2 - \frac{2}{3^x} + \frac{x}{2} - \frac{1}{3}\)

\(6x^2 - 4n + 3n - 2 = 0\)

\(6x^2 - x - 2 = 0\)

553.

Find the 6th term of the sequence \(\frac{2}{3} \frac{7}{15} \frac{4}{15}\),...

A.

-\(\frac{1}{3}\)

B.

-\(\frac{1}{5}\)

C.

-\(\frac{1}{15}\)

D.

\(\frac{1}{9}\)

Correct answer is A

a = \(\frac{2}{3}\), d = \(\frac{7}{15}\) - \(\frac{2}{3}\)

= 7 - 10

= \(\frac{-3}{15}\)

d = - \(\frac{-1}{5}\)

T6 = a + 5d

= \(\frac{2}{3}\) + 5(\(\frac{-1}{5}\)

= \(\frac{2}{3}\) - 1

= \(\frac{2 - 3}{3}\)

= \(\frac{-1}{3}\)

554.

Simplify the expression \(\frac{a^2 b^4 - b^2 a^4}{ab(a + b)}\)

A.

\(a^2 - b^2\)

B.

\(b^2 - a^2\)

C.

\(a^2b - ab^2\)

D.

\(ab^2 - a^2b\)

Correct answer is D

\(\frac{a^2 b^4 - b^2 a^4}{ab(a + b)}\) = \(\frac{a^2 b^24(b^2 - a^2}{ab(a + b)}\)

= \(\frac{ab [(b - a) (b + a)]}{a + b}\)

= ab(b - a)

= \(ab^2 - a^2b\)

555.

Three exterior angles of a polygon are 30\(^o\), 40\(^o\) and 60\(^o\). If the remaining exterior angles are 46\(^o\) each, name the polygon.

A.

decagon

B.

nonagon

C.

octagon

D.

hexagon

Correct answer is C

Sum of all exterior angles is 360\(^o\)

360\(^o\) (30\(^o\) - 40\(^o\))

360 - (130\(^o\))

230\(^o\)

remaining is 46\(^o\) = \(\frac{230}{46}\) = 5

5 + 3 = 8 sides; Octagon