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.

716.

Find the gradient of the line joining the points (3, 2) and (1, 4)

A.

3/2

B.

2/1

C.

-1

D.

3/2

Correct answer is C

Gradient of line joining points (3, 2), (1, 4)

Gradient = \(\frac{\text{Change in Y}}{\text{Change in X}}\)

= \(\frac{y_2 - Y_1}{x_2 - x_1}\)\)

(X1, Y1) = (3, 2)

(X2, Y2) = (1, 4)

Gradient = \(\frac{4 − 2}{1 + 3}\)

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

= −1

717.

The operation * on the set R of real number is defined by x * y = 3x + 2y − 1, find 3* − 1

A.

9

B.

- 9

C.

6

D.

- 6

Correct answer is C

x * y is an operation on 3x + 2y − 1

Find 3A − 1

x = 3, y = −1

3 * − 1 on 3x + 2y − 1

3(3) + 2(−1) −1

= 9 − 2 − 1

= 6

718.

Make S the subject of the relation
p = s + \(\frac{sm^2}{nr}\)

A.

s = \(\frac{nrp}{nr + m^2}\)

B.

s = nr + \(\frac{m^2}{mrp}\)

C.

s = \(\frac{nrp}{mr}\) + m2

D.

s = \(\frac{nrp}{nr}\) + m2

Correct answer is A

p = s + \(\frac{sm^2}{nr}\)

p = s + ( 1 + \(\frac{m^2}{nr}\))

p = s (1 + \(\frac{nr + m^2}{nr}\))

nr × p = s (nr + m2)

s = \(\frac{nrp}{nr + m^2}\)

719.

Factorize completely X2+2XY+Y2+3X+3Y-18

A.

(x + y + 6)(x + y -3)

B.

(x - y - 6)(x - y + 3)

C.

(x - y + 6)(x - y - 3)

D.

(x + y - 6)(x + y + 3)

Correct answer is A

\(x^{2} + 2xy + y^{2} + 3x + 3y - 18\)

\(x^{2} + 2xy + 3x + y^{2} + 3y -18\)

\(x^{2} + 2xy - 3x + 6x + y^{2} -3y + 6y -18\)

\(x^{2} + 2xy -3x + y^{2} -3y + 6x + 6y -18\)

\(x^{2} + xy -3x + xy + y^{2} - 3y + 6x + 6y -18\)

x(x + y - 3) + y(x + y - 3) + 6(x + y - 3)

= (x + y - 3)(x + y + 6)

= (x + y + 6)(x + y -3)

720.

In the diagram above MN is a chord of a circle KMN centre O and radius 10cm. If < MON = 140°, find, to the nearest cm, the length of the chord MN.

A.

10cm

B.

19cm

C.

17cm

D.

12cm

Correct answer is B

Find the diagram
Sin 70°

x = 10 Sin 70°

= 9.3969

Hence, length of chord MN = 2x

= 2 × 9.3969

= 18.79

= 19cm (nearest cm)