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.

2,156.

If the sum of the 8th and 9th terms of an arithmetic progression is 72 and the 4th term is -6, find the common difference

A.

4

B.

8

C.

6\(\frac{2}{3}\)

D.

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

Correct answer is D

Let the first term and common difference = a & d respectively.

\(T_{n} = \text{nth term} = a + (n - 1) d\) (A.P)

Given: \(T_{4} = -6 \implies a + 3d = -6 ... (i)\)

\(T_{8} + T_{9} = 72\)

\(\implies a + 7d + a + 8d = 72 \implies 2a + 15d = 72 ... (ii)\)

From (i), \(a = -6 - 3d\)

\(\therefore\) (ii) becomes \(2(-6 - 3d) + 15d = 72\)

\(-12 - 6d + 15d = 72 \implies 9d = 72 + 12 = 84\)

\(d = \frac{84}{9} = 9\frac{1}{3}\)

2,157.

The solutions of x2 - 2x - 1 = 0 are the points of intersection of two graphs. if one of the graphs is y = 2 + x - x2, find the second graph

A.

y = 1 - x

B.

y = 1 + x

C.

y = x - 1

D.

y = 3x + 3

Correct answer is A

The second graph is 

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

= \(1 - x\)

2,158.

For what values of x is the curve y = \(\frac{x^2 + 3}{x + 4}\) decreasing?

A.

-3 < x \(\leq\) 0

B.

-3 \(\geq\) x < 0

C.

0 < x < 3

D.

0 \(\leq\) x \(\leq\) 3

Correct answer is D

No explanation has been provided for this answer.

2,159.

What is the solution of the equation x2 - x - 1 + 0?

A.

x = 1.6 and x = -0.6

B.

x = -1.6 and x = 0.6

C.

x = 1.6 and x = 0.6

D.

x = -1.6 and x = -0.6

Correct answer is A

\(x^{2} - x - 1 = 0\)

Using the quadratic formula, 

\(x = \frac{-b \pm \sqrt{b^{2} - 4ac}}{2a}\)

a = 1, b = -1, c = -1.

\(x = \frac{-(-1) \pm \sqrt{(-1)^{2} - 4(1)(-1)}}{2(1)}\)

\(x = \frac{1 \pm \sqrt{1 + 4}}{2} = \frac{1 \pm \sqrt{5}}{2}\)

\(x = \frac{1 + 2.24}{2} ; x = \frac{1 - 2.24}{2}\)

\(x = \frac{3.24}{2}; x = \frac{-1.24}{2}\)

\(x = 1.62 ; x = -0.61 \)

\(x \approxeq 1.6; -0.6\)

2,160.

Simplify \(\frac{x - y}{x^{\frac{1}{3}} - x^{\frac{1}{3}}}\)

A.

x2 + xy + y2

B.

x\(\frac{2}{3}\) + x \(\frac{1}{3}\) + y\(\frac{2}{3}\)

C.

x\(\frac{2}{3}\) - x\(\frac{1}{3}\)y\(\frac{2}{3}\)

D.

y\(\frac{2}{3}\)

Correct answer is B

No explanation has been provided for this answer.