WAEC Mathematics Past Questions & Answers - Page 305

1,521.

Simplify: \((\frac{16}{81})^{\frac{1}{4}}\)

A.

8/27

B.

1/3

C.

4/9

D.

2/3

E.

-4/3

Correct answer is D

\((\frac{16}{81})^{\frac{1}{4}}\)

= \(((\frac{2}{3})^{4})^{\frac{1}{4}}\)

= \(\frac{2}{3}\)

1,522.

The nth term of a sequence is given by 3.2\(^{n-2}\). Write down the first three terms of the sequence.

A.

2/3, 0, 6

B.

3/2, 3, 6,

C.

2/3, 3, 8/3

D.

2/3, 3/4, 6

E.

2/3, 3, 1/3

Correct answer is B

\(T_n = 3. 2^{n - 2} \)

\(T_{1} = 3. 2^{1 - 2} = 3. 2^{-1} \)

\(T_1 = \frac{3}{2} \)

\(T_2 = 3. 2^{2 - 2} \)

\(T_2 = 3. 2^0  = 3\)

\(T_3 = 3. 2^{3 - 2} = 3. 2^1 \)

\(T_3 = 6\)

The first 3 terms of the sequence are \(\frac{3}{2}\), 3 and 6.

1,523.

A bricklayer measured the length of a wall and obtained 4.10m. If the actual length of the wall is 4.25m, find his percentage error.

A.

3 9/17%

B.

3 27/41%

C.

15%

D.

35 5/17%

E.

36 24/41%

Correct answer is A

Error = 4.25 - 4.10 = 0.15

% error = \(\frac{0.15}{4.25} \times 100%\)

= \(\frac{15}{\frac{17}{4}} = \frac{15 \times 4}{17}\)

= \(3\frac{9}{17} %\)

1,524.

Convert 77 to a number in base two

A.

1001 101

B.

111001

C.

100110

D.

10101

E.

10011

Correct answer is A

\(\begin{array}{c|c} 2 & 77 \\ \hline 2 & 38 R1 \\ 2 & 19 R0 \\ 2 & 9 R1 \\ 2 & 4 R1 \\ 2 & 2 R0 \\ 2 & 1 R0 \\ & 0 R1\end{array}\)

77ten = 1001101two

1,525.

If x varies over the set of real numbers, which of the following is illustrated in the diagram above?

A.

-3

B.

-3≤x<2

C.

-3

D.

-3≤x≤2

E.

x≥2

Correct answer is B

No explanation has been provided for this answer.