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.

1,796.

Simplify \(\frac{5^x \times 25^{x - 1}}{125^{x + 1}}\)

A.

52x + 1

B.

5x + 1

C.

5-5

D.

52

E.

53

Correct answer is C

\(\frac{5^x \times 25^{x - 1}}{125^{x + 1}}\) = \(\frac{5^x \times 5^{2x - 2}}{5^{3x + 3}}\)

= \(\frac{5^{x + 2x - 2}}{5^{3x + 3}}\)

= \(\frac{5^{3x - 2}}{5^{3x + 3}}\)

= 5\(^{3x - 2 - 3x - 3}\)

= 5\(^{-5}\)

1,797.

Rationalize the denominator of the expression \(\frac{6 + 2\sqrt{5}}{4 - 3\sqrt{6}}\)

A.

\(\frac{12+ 4\sqrt{5 + 7} 5 + 6\sqrt{3}}{39}\)

B.

\(\frac{-(24 + 18\sqrt{6} + 8\sqrt{5} + 6\sqrt{30})}{38}\)

C.

\(\frac{24 + 3\sqrt{6 + 8} 5 + 6\sqrt{30}}{19}\)

D.

\(\frac{-15 + 3\sqrt{5 + 18} 5 + 6\sqrt{30}}{36}\)

E.

\(\frac{-(12 + 4\sqrt{5} +9\sqrt{6} + 3\sqrt{30})}{19}\)

Correct answer is B

Rationalize using the reciprocal of the denominator to multiply through 

(i.e. Multiply both numerator and denominator using \(4 + 3\sqrt{6}\) )

Watch your signs in the course of this.

1,798.

A square of cardboard is taped at the perimeter by a piece of ribbon 20cm long. What is the area of the board?

A.

20sq.cm

B.

100sq.cm

C.

25sq.cm

D.

16sq.cm

E.

36sq.cm

Correct answer is C

Area of a square = 4(5) where S is each sides of the square

Perimeter = 20(given)

4S = 20

S = \(\frac{20}{4}\)

= 5

Area s2 = 52

= 25

1,799.

Multiply (3x + 5y + 4z) by (2x - 3y + z)

A.

6x2 + xy - 15y2 + 4z2 + 11xz - 7yz

B.

6x2 + 3xy - 15y2 + 4z2

C.

6x2 + 3xy - y2 + 4z2

D.

6x2 + 3xy - 15y + z2

Correct answer is A

(3x + 5y + 4z)(2x - 3y + z)

6x2 + 9xy + 3x2 + 10xy - 15y2 + 5yz + 8xz - 12yz + 4z2

= 6x2 + xy - 15y2 + 4z2 + 11xz - 7yz

1,800.

A trader goes to Ghana for y days with y cedis. For the first x days, he spends X cedis per day. The amount he has to spend per day for the rest of his stay is

A.

\(\frac{y(y - x)}{y - x}\) cedis

B.

\(\frac{Yy - Xx)}{y - x}\) cedis

C.

\(\frac{Y - Xy)}{y - x}\) cedis

D.

\(\frac{Y - X}{y - x}\) cedis

E.

\(\frac{Y - Xx}{y - x}\) cedis

Correct answer is E

The amount he has to spend per day for the rest of his stay is \(\frac{Y - Xx}{y - x}\) cedis