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.

3,996.

Three consecutive positive integers k, l and m are such that l\(^2\) = 3(k+m). Find the value of m.

A.

4

B.

5

C.

6

D.

7

Correct answer is D

l\(^2\) = 3 (k + m)

Since they are consecutive positive numbers, we have

l = k+1, m = k+2.

\(\to\) (k+1)\(^2\) = 3(k + k + 2)

k\(^2\) + 2k + 1 = 3(2k + 2)

k\(^2\) + 2k + 1 = 6k + 6

k\(^2\) + 2k - 6k + 1 - 6 = 0

k\(^2\) - 4k - 5 = 0

k\(^2\) - 5k + k - 5 = 0

k(k - 5) + 1(k - 5) = 0

k = -1 or 5

Since k, l and m are positive, then k = 5.

m = k + 2 = 5 + 2

= 7.

3,997.

Tope bought X oranges at N5.00 each and some mangoes at N4.00 each. if she bought twice as many mangoes as oranges and spent at least N65.00 and at most N130.00, find the range of values of X.

A.

4≤X≤5

B.

5≤X≤8

C.

5≤X≤10

D.

8≤X≤10

Correct answer is C

Number of oranges = X; Costing N5X.

Number of mangoes = 2X; Costing N8X.

\(\therefore 65 \leq 5X + 8X \leq 130\)

\(5 \leq X \leq 10\)

 

3,998.

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

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

Expand the options and collect like terms to check which gives the presented expression.

Expansion of Options A:

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

Collect like terms: \(x^2 + xy + xy + y^2 +6x - 3x +6y - 3y - 18\)

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

3,999.

A binary operation * is defined by a*b = ab+a+b for any real number a and b. if the identity element is zero, find the inverse of 2 under this operation.

A.

2/3

B.

1/2

C.

-1/2

D.

-2/3

Correct answer is D

\(a*a^{-1} = aa^{-1} + a + a^{-1} = e\)

if e = 0

\(2.2^{-1} + 2 + 2^{-1} = 0\)

collecting like terms, we have:

\(3.2^{-1} + 2 = 0\)

= \(2^{-1}\) = -\(\frac{2}{3}\)

3,000.

The sum of two numbers is twice their difference. If the difference of the numbers is P, find the larger of the two numbers

A.

p/2

B.

3p/2

C.

5p/2

D.

3p

Correct answer is B

Let the numbers be x and y
x+y = 2p.....(i)
x-y = p......(ii)
2x = 3p
x = 3p/2