1999 - WAEC Mathematics Past Questions and Answers - page 1
The side of a rhombus is 10cm long, correct to the nearest whole number. Between what limits should the perimeter P lie?
If the side = 10 cm, correct to the nearest whole number, then
The side ranges from 9.5 cm to 10.5 cm. (9.5 \(\leq\) s < 10.5)
Perimeter of a rhombus = 4 x side
\(\therefore\) 4 x 9.5 \(\leq\) perimeter < 4 x 10.5
= 38 cm \(\leq\) P < 42 cm
Simplify log\(_7\) 8 - log\(_7\) 2 + log\(_7\) 4.
log\(_7\) 8 - log\(_7\) 2 + log\(_7\) 4
= log\(_7\) (8/2 x 4)
= log\(_7\) 16
= 4 log\(_7\) 2
If \(K\sqrt{28}+\sqrt{63}-\sqrt{7}=0\), find K.
\(K\sqrt{28}+\sqrt{63}-\sqrt{7}=0\
2K\sqrt{7}+3\sqrt{7}-\sqrt{7}=0\
2K\sqrt{7}=-2\sqrt{7}\
K=\frac{-2\sqrt{7}}{2\sqrt{7}}\
K=-1\)
From a set \(A = [3, \sqrt{2}, 2\sqrt{3}, \sqrt{9}, \sqrt{7}]\), a number is selected at random. Find the probability that is a rational number
\(A = {3, \sqrt{2}, 2\sqrt{3}, \sqrt{9}, \sqrt{7}}\)
n(A) = 5
Let the rational nos = R
n(R) = 2 (3, \(\sqrt{9}\))
P(R) = 2/5
The pie chart illustrate the amount of private time a student spends in a week studying various subjects. use it to answer the question below
Find the value of K
Total angle in a circle = 360°
\(\therefore\) 105 + 75 + 2k + k + 3k = 360°
6k = 360 - 180 = 180
k = 180/6 = 30°
The pie chart illustrate the amount of private time a student spends in a week studying various subjects. use it to answer the question below
If he sends \(2\frac{1}{2}\) hours week on science, find the total number of hours he studies in a week
Let x represent the total number of hours spent per week
\(∴ \frac{75}{360} \times x = \frac{5}{2}\
∴ x = \frac{360 \times 5}{725 \times 2}=12 hours\)
A group of 11 people can speak either English or French or Both. Seven can speak English and six can speak French. What is the probability that a person chosen at random can speak both English and French?
Let the number of people that speak both English and French = x
Then (7 - x) + x + (6 - x) = 11
13 - x = 11 \(\implies\) x = 2.
\(\therefore\) P(picking a person that speaks both languages) = 2/11
The interior angle of a regular polygon is twice the exterior angle. How many sides has the polygon?
Let the exterior angle = d
Note: Exterior angle + Interior angle = 180°
\(\implies\) d + 2d = 180°
3d = 180° \(\implies\) d = 60°
Recall, exterior angle = \(\frac{360}{\text{no of sides}}\)
\(\therefore \text{No of sides} = \frac{360}{60}\)
= 6 sides
Which of the following figures have one line of symmetry only? I. Isosceles triangle II. Rhombus III. Kite
Isosceles triangle and Kite shapes have 1 line of symmetry each while the rhombus has 2 lines of symmetry.
In the diagram above, |XR| = |RY| = |YZ| and ∠XRY = ∠YRZ = 62o, Calculate ∠XYZ
In triangle RXY, < RXY = < RYX (base angles of an isosceles triangle)
\(\implies\) 180° - 62° = 2 < RYX
118° = 2 < RYX \(\implies\) < RYX = 59°
In triangle RYZ, < RZY = 62° (base angles of an isosceles triangle)
\(\therefore\) < RYZ = 180° - (62° + 62°)
= 180° - 124° = 56°
\(\therefore\) < XYZ = 56° + 59°
= 115°