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.

281.

Correct 241.34(3 x 10\(^{-3}\))\(^2\) to 4 significant figures

A.

0.0014

B.

0.001448

C.

0.0022

D.

0.002172

Correct answer is D

first work out the expression and then correct the answer to 4 s.f = 241.34..............(A)

(3 x 10-\(^3\))\(^2\)............(B)

= 3\(^2\)x\(^2\)

= \(\frac{1}{10^3}\) x \(\frac{1}{10^3}\)

(Note that x\(^2\) = \(\frac{1}{x^3}\))

= 24.34 x 3\(^2\) x \(\frac{1}{10^6}\)

= \(\frac{2172.06}{10^6}\)

= 0.00217206

= 0.002172(4 s.f)

282.

Find the derivative of the function y = 2x\(^2\)(2x - 1) at the point x = -1?

A.

18

B.

16

C.

-4

D.

-6

Correct answer is B

y = 2x\(^2\)(2x - 1)
y = 4x\(^3\) - 2x\(^2\)
dy/dx = 12x\(^2\) - 4x
at x = -1
dy/dx = 12(-1)\(^2\) - 4(-1)
= 12 + 4
= 16

283.

Find the value of p if the line which passes through (-1, -p) and (-2,2) is parallel to the line 2y+8x-17=0?

A.

\(\frac{-2}{7}\)

B.

\(\frac{7}{6}\)

C.

\(\frac{-6}{7}\)

D.

2

Correct answer is D

Line:  2y+8x-17=0 

recall y = mx + c

2y = -8x + 17

y = -4x  + \(\frac{17}{2}\)

Slope m\(_1\) = 4

parallel lines: m\(_1\). m\(_2\) = -4

where Slope ( -4) = \(\frac{y_2 - y_1}{x_2 - x_1}\) at points (-1, -p) and (-2,2)

-4( \(x_2 - x_1\) ) = \(y_2 - y_1\) 

-4 ( -2 - -1) = 2 - -p

p = 4 - 2 = 2

284.

A trapezium has two parallel sides of lengths 5cm and 9cm. If the area is 91cm\(^2\), find the distance between the parallel sides

A.

13 cm

B.

4 cm

C.

6 cm

D.

7 cm

Correct answer is A

Area of Trapezium = 1/2(sum of parallel sides) * h
91 = \(\frac{1}{2}\) (5 + 9)h

cross multiply
91 = 7h
h = \(\frac{91}{7}\)
h = 13cm

285.

Determine the maximum value of y=3x\(^2\) + 5x - 3

A.

6

B.

0

C.

2

D.

No correct option

Correct answer is D

y=3x\(^2\) + 5x - 3

dy/dx = 6x + 5

as dy/dx = 0

6x + 5 = 0

x = \(\frac{-5}{6}\)

Maximum value: 3 \( ^2{\frac{-5}{6}}\)  + 5 \(\frac{-5}{6}\) - 3

3 \(\frac{75}{36}\) - \(\frac{25}{6}\) - 3

Using the L.C.M. 36

= \(\frac{25 - 50 - 36}{36}\)

= \(\frac{-61}{36}\)

No correct option