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.

1,076.

Find the 19th term of the A.P. \(\frac{5}{6}\), \(\frac{8}{6}\), \(\frac{11}{6}\).................

A.

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

B.

9

C.

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

D.

9\(\frac{5}{6}\)

E.

10

Correct answer is D

first term (a) = \(\frac{5}{6}\)

common difference =   \(\frac{8}{6}\) - \(\frac{5}{6}\) → \(\frac{3}{6}\) or \(\frac{1}{2}\)

A.P formula → T\(_n\) = a + (n - 1)d
T\(_n\) = \(\frac{5}{6}\) + (19 - 1)\(\frac{1}{2}\)
T\(_n\) = \(\frac{5}{6}\) + 9

→ 9\(\frac{5}{6}\)

1,077.

Mr Aborowa bought a car for N200,000.00 and later sold it for N170,000.00. What is the percentage loss?

A.

11.60%

B.

7.60%

C.

15%

D.

17.65%

Correct answer is C

Using these:

Loss = C.p - S.p

: Percentage Loss = ( Loss X 100) ÷ C.p

=15 %

1,078.

If s = \(\sqrt{(\frac{a^2}{x^2} - \frac{b^2}{y^2})}\)what does y equal?

A.

\(\sqrt{\frac{(b^2 - a^2)}{(s^2 - x^2)}}\)

B.

\(\sqrt{\frac{(b^2 - a^2)}{(s^2 \times 2)}}\)

C.

\(\sqrt{\frac{x^2 - a^2 - b^2}{s}}\)

D.

\(\frac{x^2 - a^2 - b^2}{s}\)

E.

\(\sqrt{\frac{(b^2 x^2)}{(a^2 - s^2 x^2)}}\)

Correct answer is E

s = \(\sqrt{(\frac{a^2}{x^2} - \frac{b^2}{y^2})}\)

s\(^2\) = \(\frac{a^2}{x^2} - \frac{b^2}{y^2}\)

\(\frac{b^2}{y^2}\) = \(\frac{a^2}{x^2}\) - s\(^2\)

\(\frac{b^2}{y^2}\) = \(\frac{a^2 - s^2 x^2}{x^2}\)

\(\frac{1}{y^2}\) = \((\frac{a^2 - s^2 x^2}{x^2}) \times \frac{1}{b^2}\)

\(\frac{1}{y^2}\) = \(\frac{a^2 - s^2 x^2}{b^2 x^2}\)

\(\therefore\) y\(^2\) = \(\frac{b^2 x^2}{a^2 - s^2 x^2}\)

y = \(\sqrt{\frac{b^2 x^2}{a^2 - s^2 x^2}}\)

1,079.

Factorize \( a^2 − b^2 − 4a + 4 \)

A.

(a + b)(a − b)

B.

(a − 2 + b)(a - 2- b)

C.

(a + 1)(a − 2 + b)

D.

(a + b) 2

Correct answer is B

The trinomial = \( a^2 − 4a + 4 \\

a^2 − b^2− 4a + 4 = (a^2 − 4a + 4) − b^2 \\

(a^2 − 2a − 2a + 4) − b^2 \\

a(a − 2)− 2(a − 2)] − b^2 \\

(a − 2)2 − b^2 \\

(a − 2 + b)(a − 2 − b )\)

1,080.

Rationalize 5 ÷ (2 − √3)

A.

3(2 + √5)

B.

2(3 + √5)

C.

5(2 + √3)

D.

3 √2 + 1

Correct answer is C

5÷ (2 − √3)

Using conjugate surds

[5 ÷ (2 − √3)]×(2 + √3) ÷ (2 + √3)]

[5(2+√3)÷((2− √3))2]

[5(2 +√3) ÷ (2)2− (√3)2]

[5(2 +√3) ÷(4− 3)]

= 5(2 + √3)