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.

1,836.

In base ten, the number 101101 (base 2) equals

A.

15

B.

4

C.

45

D.

32

E.

90

Correct answer is C

(101101)2 \(\begin{array}{c|c} 2^5 & 2^4 & 2^3 & 2^2 & 2^1 & 2^o\\ \hline 1 & 0 & 1 & 1 & 0 & 1\end{array}\)

= 1 x 25 + 0 x 24 + 1 x 23 + 1 x 22 + 0 x 21 + 1 x 2o

= 32 + 0 + 8 + 4 + 0 + 1

= (45)10

1,837.

After getting a rise of 15%, a man's new monthly salary is N345. How much per month did he earn before the increase?

A.

N330

B.

N396.75

C.

N300

D.

N293.25

E.

N360

Correct answer is C

Let x represent his monthly salary before increase 15% of

x = 345

% profit = (100 + 15)%

= 115%

\(\frac{115}{100}\)x = 345

115x = 34500

x = N300.00

1,838.

In \(\bigtriangleup\)PQR, PQ = 10cm, QR = 8cm and RP = 6cm, the perpendicular RS is drawn from R to PQ. Find the length of RS

A.

4cm

B.

32cm

C.

\(\frac{30}{7}\)

D.

\(\frac{40}{7}\)

E.

4.8cm

Correct answer is E

Cos Q = \(\frac{r^2 + p^2 - q^2}{2rp}\)

= \(\frac{10^2 + 8^2 - 6^2}{2(10)(8)}\)

= \(\frac{164 - 36}{160}\)

= \(\frac{128}{160}\)

= 0.8

Q = Cos-1 o.8

= 37o x rep. from rt< RSQ, Let RS = x

\(\frac{x}{sin 37^o}\) = \(\frac{8}{sin 90^o}\)

but sin 90o = 1

x = 8 sin 37o

x = 4.8cm

1,839.

(3.2)2 - (1.8)2 equals

A.

7.0

B.

2.56

C.

13.48

D.

2.0

E.

0.07

Correct answer is A

(3.2)2 - (1.8)2 = (3.2 + 1.8)(3.2 - 1.8)

= 5 x 1.4

= 7

1,840.

If the value of \(\pi\) is taken to be \(\frac{22}{7}\), the area of a semi-circle of diameter 42m is

A.

5544m2

B.

1386m2

C.

132m2

D.

264m2

E.

693m2

Correct answer is E

\(\pi\) = \(\frac{22}{7}\), Diameter D = 42m

Area of a circle = \(\frac{\pi D^2}{4}\) when a diameter is given

area of a semicircle \(\frac{\pi D^2}{4}\) x \(\frac{1}{2}\)

= \(\frac{22}{7}\) x \(\frac{4262}{4}\) x \(\frac{1}{2}\)

= \(\frac{11}{7} \times 441\)

= 693m\(^{2}\)