Year : 
2020
Title : 
Mathematics (Core)
Exam : 
WASSCE/WAEC MAY/JUNE

Paper 1 | Objectives

1 - 10 of 50 Questions

# Question Ans
1.

Evaluate and correct to two decimal places, 75.0785 - 34.624 + 8.83

A. 30.60

B. 50.29

C. 50.28

D. 30.62

Detailed Solution

75.0785
- 34.624
--------------
40.4545
+ 9.83
--------------
50.28 to 2d.p
2.

If X = {x : x < 7} and Y = {y:y is a factor of 24} are subsets of \(\mu\) = {1, 2, 3...10} find X \(\cap\) Y.

A. {2, 3, 4, 6}

B. {1, 2, 3, 4, 6}

C. {2, 3, 4, 6, 8}

D. {1, 2, 3, 4, 6, 8}

Detailed Solution

\(\mu\) = {1, 2, 3, 4..., 10}
X = {1, 2, 3, 4, 5, 6}
Y = {1, 2, 3, 4, 6, 8}
Therefore;
X \(\cap\) Y = {1, 2, 3, 4, 6}
3.

Simplify; [(\(\frac{16}{9}\))\(^{\frac{-3}{2}}\) x 16\(^{\frac{-3}{2}}\)]\(^{\frac{1}{3}}\)

A. \(\frac{3}{4}\)

B. \(\frac{9}{16}\)

C. \(\frac{3}{8}\)

D. \(\frac{1}{4}\)

Detailed Solution

[(\(\frac{16}{9}\))\(^{\frac{-3}{2}}\) x 16\(^{\frac{-3}{2}}\)]\(^{\frac{1}{3}}\)
= [(\(\frac{9}{16}\))]\(^{\frac{3}{2}}\) x [(\(\frac{1}{16}\))\(^{\frac{3}{4}}\)]\(^{\frac{1}{3}}\)
= [(\(\sqrt{\frac{9}{10}}\))\(^3\) x (4\(\sqrt{\frac{1}{16}})^3\)]\(^{\frac{1}{3}}\)
= [(\(\frac{3}{4})^3 \times (\frac{1}{2})^3\)]\(^\frac{1}{3}\)
(\(\frac{27}{64} \times \frac{1}{8}\))\(^\frac{1}{3}\) = \({3}\sqrt{\frac{27}{64} \times \frac{1}{8}}\)
= \(\frac{3}{4} \times \frac{1}{2}\) = \(\frac{3}{8}\)
4.

Express 1 + 2 log10\(^3\) in the form log10\(^9\)

A. log10\(^{90}\)

B. log10\(^{19}\)

C. log10\(^{9}\)

D. log10\(^{6}\)

Detailed Solution

1 + 2log\(_{10}^3\)
= log\(_{10}^{10} + log_{10}^{3^2}\)
= log\(_{10}^{10} + log_{10}^{9}\)
= log\(_{10}^{10 \times 90}\) = log\(_{10}^{90}\)
5.

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

A. 8

B. 7

C. 6

D. 5

Detailed Solution

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
6.

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

Detailed Solution

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
7.

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

Detailed Solution

\(\frac{\sqrt{3} + \sqrt{5}}{\sqrt{5}}\) = 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\(\frac{1}{5}\)

8.

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

A. 24

B. 22

C. 20

D. 16

Detailed Solution

2(\(x^2 - y^2\))
= 2(x + y)(x - y)
= 2(3 + (-1))(3 - (-1))
= 2(2)(4) = 16
9.

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

Detailed Solution

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
10.

The implication x \(\to\) y is equivalent to

A. ~ y \(\to\) ~ x

B. y \(\to\) ~ x

C. ~ x \(\to\) ~ y

D. y \(\to\) x

A

1.

Evaluate and correct to two decimal places, 75.0785 - 34.624 + 8.83

A. 30.60

B. 50.29

C. 50.28

D. 30.62

Detailed Solution

75.0785
- 34.624
--------------
40.4545
+ 9.83
--------------
50.28 to 2d.p
2.

If X = {x : x < 7} and Y = {y:y is a factor of 24} are subsets of \(\mu\) = {1, 2, 3...10} find X \(\cap\) Y.

A. {2, 3, 4, 6}

B. {1, 2, 3, 4, 6}

C. {2, 3, 4, 6, 8}

D. {1, 2, 3, 4, 6, 8}

Detailed Solution

\(\mu\) = {1, 2, 3, 4..., 10}
X = {1, 2, 3, 4, 5, 6}
Y = {1, 2, 3, 4, 6, 8}
Therefore;
X \(\cap\) Y = {1, 2, 3, 4, 6}
3.

Simplify; [(\(\frac{16}{9}\))\(^{\frac{-3}{2}}\) x 16\(^{\frac{-3}{2}}\)]\(^{\frac{1}{3}}\)

A. \(\frac{3}{4}\)

B. \(\frac{9}{16}\)

C. \(\frac{3}{8}\)

D. \(\frac{1}{4}\)

Detailed Solution

[(\(\frac{16}{9}\))\(^{\frac{-3}{2}}\) x 16\(^{\frac{-3}{2}}\)]\(^{\frac{1}{3}}\)
= [(\(\frac{9}{16}\))]\(^{\frac{3}{2}}\) x [(\(\frac{1}{16}\))\(^{\frac{3}{4}}\)]\(^{\frac{1}{3}}\)
= [(\(\sqrt{\frac{9}{10}}\))\(^3\) x (4\(\sqrt{\frac{1}{16}})^3\)]\(^{\frac{1}{3}}\)
= [(\(\frac{3}{4})^3 \times (\frac{1}{2})^3\)]\(^\frac{1}{3}\)
(\(\frac{27}{64} \times \frac{1}{8}\))\(^\frac{1}{3}\) = \({3}\sqrt{\frac{27}{64} \times \frac{1}{8}}\)
= \(\frac{3}{4} \times \frac{1}{2}\) = \(\frac{3}{8}\)
4.

Express 1 + 2 log10\(^3\) in the form log10\(^9\)

A. log10\(^{90}\)

B. log10\(^{19}\)

C. log10\(^{9}\)

D. log10\(^{6}\)

Detailed Solution

1 + 2log\(_{10}^3\)
= log\(_{10}^{10} + log_{10}^{3^2}\)
= log\(_{10}^{10} + log_{10}^{9}\)
= log\(_{10}^{10 \times 90}\) = log\(_{10}^{90}\)
5.

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

A. 8

B. 7

C. 6

D. 5

Detailed Solution

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
6.

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

Detailed Solution

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
7.

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

Detailed Solution

\(\frac{\sqrt{3} + \sqrt{5}}{\sqrt{5}}\) = 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\(\frac{1}{5}\)

8.

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

A. 24

B. 22

C. 20

D. 16

Detailed Solution

2(\(x^2 - y^2\))
= 2(x + y)(x - y)
= 2(3 + (-1))(3 - (-1))
= 2(2)(4) = 16
9.

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

Detailed Solution

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
10.

The implication x \(\to\) y is equivalent to

A. ~ y \(\to\) ~ x

B. y \(\to\) ~ x

C. ~ x \(\to\) ~ y

D. y \(\to\) x

A