Mathematics Grade 9 – School Exam Preparation
1. Look at the data below!
Score
5
6
7
8
Frequency
3
x
8
8
a. If the median is 7.5, determine x!
b. Determine the mean from table above if x known from 1a!
9
5
2. Look at the data below!
Age
10
15
20
25
30
Frquency
8
x
6
7
5
a. If the median is 20, determine the smallest and biggest x possible!
b. If the mean is 20.375, determine x!
10
3
35
4
3. If the mean of five observations x, x + 4, x + 6, x + 8 and x + 12 is 16, find the value of x.
4. A class of 16 boys has an average weight of 50.25 kg, while the remaining 8 boys have an
average weight of 45.15 kg. Calculate the average weight of all boys in the class.
5. Look at the picture below!
Line g is parallel with line f. Determine
the equation of line g.
6. Look at the picture below!
Line p is perpendicular with line q.
Determine the equation of line q.
7. Expand and simplify the equation below!
a. 2(𝑥 2 + 𝑥 + 9) − (2𝑥 2 + 9𝑥 − 8)
b. 2x(x + 5) + 3x(x – 7)
c. (3𝑥 − 5)(2𝑥 + 1) − 2(𝑥 − 1)2
8. Find x!
2𝑥+1
a. 2(𝑥 + 1) = 5 + 1
1
𝑥
1
b. 𝑥 − 2 = 3 + 2 6
9. Find the sum of positive numbers that can be divided by 3 between 200 and 400!
10. Find the sum of positive numbers that can be divided by 4 and 5 between 600 and 1100!
11. In the kite, one diagonal is 12 cm longer than the other diagonal. If the area of kite is 182
cm2, then find the length of both diagonal!
12. Find x!
a.
13.
b.