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.

3,966.

if (x - 1), (x + 1) and (x - 2) are factors of the polynomial ax3 + bx2 + cx - 1, find a, b, c in that order.

A.

-1/2, 1., 1/2

B.

1/2, 1, 1/2

C.

1/2, 1, -1/2

D.

1/2, -1, 1/2

Correct answer is A

This is a polynomial of the 3rd order, thus x should have three answers. Use the factors given to get values of x as 1, -1 and -2.

Form three equations, and carry out elimination and subsequent substitution to get a = -1/2, b = 1, and c = 1/2

3,967.

Evaluate (1/2 - 1/4 + 1/8 - 1/16 + ...) - 1

A.

2/3

B.

zero

C.

-2/3

D.

-1

Correct answer is C

S = a/(1-r), where a = 1/2, r = -1/2.

S = 1/2 3/2 = 1/2 x 3/2 = 1/3.
1/3 - 1 = -2/3

3,968.

Find the inverse of p under the binary operation * defined by p*q = p + q - pq, where p and q are real numbers and zero is the identity

A.

p

B.

p -1

C.

p/(p-1)

D.

p/(p+1)

Correct answer is C

If P-1 is the inverse of P and O is the identity, Then P-1 * P = P * P-1 = 0
i.e. P-1 + P - P-1.P = 0
P-1 - P-1.P = -P
P-1(1 - P) = -P
P-1 = -P/(P-1)
= P/(P-1)

3,969.

The 3rd term of an A.P is 4x - 2y and the 9th term is 10x - 8y. Find the common difference.

A.

19x - 17y

B.

8x - 4y

C.

x - y

D.

2x

Correct answer is C

n = 3, U\(_3\) = 4x - 2y,
U\(_n\) = a + (n-1)d,
4x - 2y = a + 2d... (1)

U\(_9\) = 10x - 8y,
10x - 8y = a + 8d... (2)

Solving (1) and (2),

subtract eqn i from ii

a-a + 8d - 2d = 10x -4x - 8y- (-2y)
6d = 6x - 8y+ 2y.
6d= 6x - 6y
6d = 6( x-y)

d = x - y
 

 

3,970.

A binary operation * is defined by a * b = a\(^b\). If a * 2 = 2 - a, find the possible values of a.

A.

1, -1

B.

1, 2

C.

2, -2

D.

1, -2

Correct answer is D

a * b = a\(^b\)

a * 2 = a\(^2\) = 2 - a

a\(^2\) + a - 2 = 0

a\(^2\) + 2a - a - 2 = 0

a(a+2) - 1(a+2) = 0

(a-1)(a+2) = 0

a = 1, -2