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.

2,841.

If \(P = \sqrt{QR\left(1+\frac{3t}{R}\right)}\), make R the subject of the formula.

A.

\(R = \frac{3Qt}{P^2 - Q}\)

B.

\(R = \frac{P^2 – 3t}{Q+1}\)

C.

\(R = \frac{P^2 + 3t}{Q - 1}\)

D.

\(R = \frac{P^2-3Qt}{Q}\)

Correct answer is D

No explanation has been provided for this answer.

2,842.

In a ∆ XYZ, /YZ/ = 6cm YXZ = 60o and XYZ is a right angle. Calculate /XZ/in cm, leaving your answer in surd form

A.

2√3

B.

4√3

C.

6√3

D.

12√3

Correct answer is B

\(sin \theta = \frac{opp}{hyp}\\
sin 60^o = \frac{|YZ|}{|XZ|}=\frac{6}{P}\\
P sin 60^o = 6\\
P = \frac{6}{sin60^o}\\
=\frac{6}{\sqrt{\frac{3}{2}}}=4\sqrt{3}\)

2,843.

Which of the following is/are not the interior angle(s) of a regular polygon?

I.108° 
II. 116°
III. 120°

A.

I only

B.

II only

C.

III only

D.

I and III only

Correct answer is B

Using the formula, \((n - 2) \times 180°\) to get the sum of the interior angles. Then we can have

\((n - 2) \times 180° = 108n\) ... (1)

\((n - 2) \times 180° = 116n\) ... (2)

\((n - 2) \times 180° = 120n\) ... (3)

Solving the above given equations, where n is not a positive integer then that angle is not the interior for a regular polygon.

(1): \(180n - 360 = 108n \implies 72n = 360\)

 \(n = 5\) (regular pentagon)

(2): \(180n - 360 = 116n \implies 64n = 360\)

 \(n = 5.625\)

(3): \(180n - 360 = 120n \implies 60n = 360\)

 \(n = 6\) (regular hexagon)

Hence, 116° is not an angle of a regular polygon.

2,844.

If \(\frac{3^{(1-n)}}{9^{-2n}}=\frac{1}{9}\) find n

A.

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

B.

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

C.

-1

D.

-3

Correct answer is C

\(\frac{3^{(1-n)}}{9^{-2n}}=\frac{1}{9}\\
3^{1-n}\times 3^{-2(-2n)} = 3^{-2}\\
1-n-2(-2n)= -2\\
1-n+4n=-2\\
n=-1\)

2,845.

Given that x ≅ 0.0102 correct to 3 significant figures, which of the following cannot be the actual value of x?

A.

0.01014

B.

0.01021

C.

0.01015

D.

0.01016

Correct answer is A

option A CANNOT BE BECAUSE THE LAST NUMBER BEFORE 1 CAN ONLY BE ROUNDED DOWN TO ZERO.