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.

326.

Solve 3x - 2y = 10 and x + 3y = 7 simultaneously

A.

x = -4 and y = 1

B.

x = -1 and y = -4

C.

x = 1 and y = 4

D.

x = 4 and y = 1

Correct answer is D

3x - 2y = 10 - - x 3

x + 3y = 7 ---x 2

------------------------

9x - 6y = 30

2x + 6y = 14

-------------------------

\(\frac{11x}{11} \frac{44}{11}\) 

x = 4

From x + 3y = 7

3y = 7 - 4

\(\frac{3y}{3}\) = \(\frac{3}{3}\)

y = 1

327.

If x = 3 and y = -1, evaluate 2(x\(^2\) - y\(^2\))

A.

24

B.

22

C.

20

D.

16

Correct answer is D

2(\(x^2 - y^2\))

= 2(x + y)(x - y)

= 2(3 + (-1))(3 - (-1))

= 2(2)(4) = 16

328.

Given that \(\frac{\sqrt{3} + \sqrt{5}}{\sqrt{5}}\) 

= x + y\(\sqrt{15}\), find the value of (x + y) 

A.

1\(\frac{3}{5}\)

B.

1\(\frac{2}{5}\)

C.

1\(\frac{1}{5}\)

D.

\(\frac{1}{5}\)

Correct answer is C

\(\frac{\sqrt{3} + \sqrt{5}}{\sqrt{5}}\)  = x + y\(\sqrt{15}\)

cross multiply to have: \(\sqrt{3}\) + \(\sqrt{5}\) =  x\(\sqrt{5}\) + 5y\(\sqrt{3}\)

Collect like roots :   x\(\sqrt{5}\) =  \(\sqrt{5}\) → x = 1

                                5y\(\sqrt{3}\) =  \(\sqrt{3}\) → y = \(\frac{1}{5}\)

∴ ( x + y ) = 1 + \(\frac{1}{5}\)

= 1\(\frac{1}{5}\)

329.

An amount of N550,000.00 was realized when a principal, x was saved at 2% simple interest for 5 years. Find the value of x

A.

N470,000.00

B.

N480,000.00

C.

N490,000.00

D.

N500,000.00

Correct answer is D

S.I = \(\frac{x \times 2 \times 5}{100}\) = 0.1x

A = P + S.I

550,000 = x + 0.1x

\(\frac{550,000}{1.1} = \frac{1.1x}{1.1}\)

x = N500,000

330.

If 101\(_{\text{two}}\) + 12y = 3.3\(_{\text{five}}\). Find the value of y

A.

8

B.

7

C.

6

D.

5

Correct answer is C

012 + 01 = 01

101\(_2\) + 12\(_y\) = 2.3\(_5\)

1 x 2\(^o\) + 0 x 2\(^o\) + 1 x2\(^2\) + 1 x y\(^o\) + 2 x y\(^1\) = 3 x 5\(^o\) + 3 x 5\(^1\)

1 + 4 + 1 + 2y = 3 + 15

6 + 2y = 18 

2y = 18 - 6

\(\frac{2y}{2} = \frac{12}{2}\)

y = 6