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.

2,626.

If x varies directly as square root of y and x = 81 when y = 9, Find x when y = 1\(\frac{7}{9}\)

A.

20\(\frac{1}{4}\)

B.

27

C.

2\(\frac{1}{4}\)

D.

36

Correct answer is D

x \(\alpha\sqrt y\)

x = k\(\sqrt y\)

81 = k\(\sqrt9\)

k = \(\frac{81}{3}\)

= 27

therefore, x = 27\(\sqrt y\)

y = 1\(\frac{7}{9}\) = \(\frac{16}{9}\)

x = 27 x \(\sqrt{\frac{16}{9}}\)

= 27 x \(\frac{4}{3}\)

dividing 27 by 3

= 9 x 4

= 36

2,627.

Solve for x and y respectively in the simultaneous equations -2x - 5y = 3. x + 3y = 0

A.

-3, -9

B.

9, -3

C.

-9,3

D.

3, -9

Correct answer is C

-2x -5y = 3 x + 3y = 0 x = -3y -2 (-3y) - 5y = -3 6y - 5y = 3 y = 3 but, x = -3y x = -3(3) x = -9 therefore, x = -9, y = 3

2,628.

Factorize completely 9y2 - 16X2

A.

(3y - 2x)(3y + 4x)

B.

(3y + 4x)(3y + 4x)

C.

(3y + 2x)(3y - 4x)

D.

(3y - 4x)(3y + 4x)

Correct answer is D

9y2 - 16x2

= 32y2 - 42x2

= (3y - 4x)(3y +4x)

2,629.

Find the remainder when X3 - 2X2 + 3X - 3 is divided by X2 + 1

A.

2X - 1

B.

X + 3

C.

2X + 1

D.

X - 3

Correct answer is A

X2 + 1 \(\frac{X - 2}{\sqrt{X^3 - 2X^2 + 3n - 3}}\)

= \(\frac {- 6X^3 + n}{-2X^2 + 2X - 3}\)

= \(\frac{(-2X^2 - 2)}{2X - 1}\)

Remainder is 2X - 1

2,630.

Make R the subject of the formula if T = \(\frac {KR^2 + M}{3}\)

A.

\(\sqrt\frac{3T - K}{M}\)

B.

\(\sqrt\frac{3T - M}{K}\)

C.

\(\sqrt\frac{3T + K}{M}\)

D.

\(\sqrt\frac{3T - K}{M}\)

Correct answer is B

T = \(\frac{KR^2 + M}{3}\)

3T = KR2 + M

KR2 = 3T - M

R2 = \(\frac{3T - M}{K}\)

R = \(\sqrt\frac{3T - M}{K}\)