1999 - WAEC Mathematics Past Questions and Answers - page 1

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

log\(_7\) 8 - log\(_7\) 2 + log\(_7\) 4

= log\(_7\) (8/2 x 4)

= log\(_7\) 16

= 4 log\(_7\) 2

\(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\)

\(A = {3, \sqrt{2}, 2\sqrt{3}, \sqrt{9}, \sqrt{7}}\)

n(A) = 5

Let the rational nos = R

n(R) = 2 (3, \(\sqrt{9}\))

P(R) = 2/5

Total angle in a circle = 360°

\(\therefore\) 105 + 75 + 2k + k + 3k = 360°

6k = 360 - 180 = 180

k = 180/6 = 30°

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\)

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

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

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°