Here are the solutions to your questions:
Q1.
a) Find the total marks
Step 1: Let the total marks be T. We are given that 45 marks is 60% of the total marks.
0.60×T=45
Step 2: Divide by 0.60 to find T.
T=0.6045
T=75
The total marks are 75.
75marks
b) How many more marks are needed to reach 80%?
Step 1: Calculate 80% of the total marks.
80%of75=0.80×75
0.80×75=60
Step 2: Find the difference between 80% of the total marks and the student's current marks.
Marks needed=60−45
Marks needed=15
The student needs 15 more marks to reach 80%.
15marks
Q2.
a) Kofi’s share
b) Ama’s share
c) Yaw’s share
Step 1: Find the total number of ratio parts.
Total ratio parts=2+3+4=9
Step 2: Find the value of one ratio part.
Value per part=9GH₵360=GH₵40
Step 3: Calculate each person's share.
a) Kofi's share:
Kofi’s share=2×GH₵40=GH₵80
GH₵80
b) Ama's share:
Ama’s share=3×GH₵40=GH₵120
GH₵120
c) Yaw's share:
Yaw’s share=4×GH₵40=GH₵160
GH₵160
Q3.
a) Find the perimeter
Step 1: The formula for the perimeter of a rectangle is P=2(L+W).
P=2(20m+15m)
P=2(35m)
P=70 m
The perimeter is 70 m.
70m
b) Find the area
Step 1: The formula for the area of a rectangle is A=L×W.
A=20m×15 m
A=300m2
The area is 300 m2.
300m2
c) Find the cost of fencing it at GH₵5 per metre
Step 1: Multiply the perimeter by the cost per metre.
Cost=70m×GH₵5/m
Cost=GH₵350
The cost of fencing is GH₵350.
GH₵350
Q4.
a) Find x
Step 1: Angles on a straight line sum to 180°.
(x+10)∘+(3x−20)∘=180∘
Step 2: Combine like terms.
4x−10=180
Step 3: Add 10 to both sides.
4x=190
Step 4: Divide by 4.
x=4190
x=47.5
The value of x is 47.5.
x=47.5
b) If one of the angles is part of a triangle, find the third angle if the other two are 50° and that angle.
Step 1: Calculate the values of the two angles on the straight line.
First angle: x+10=47.5+10=57.5∘
Second angle: 3x−20=3(47.5)−20=142.5−20=122.5∘
Let's use the first angle, 57.5∘, as "that angle" for the triangle.
Step 2: The sum of angles in a triangle is 180°.
Third angle=180∘−50∘−57.5∘
Third angle=130∘−57.5∘
Third angle=72.5∘
The third angle is 72.5°.
72.5∘
Q5.
a) What was the original price?
Step 1: A 10% discount means the shirt was sold for 100%−10%=90% of its original price.
Let the original price be P.
0.90×P=GH₵180
Step 2: Divide by 0.90 to find P.
P=0.90GH₵180
P=GH₵200
The original price was GH₵200.
GH₵200
b) A shopkeeper bought goods for GH₵450 and sold them for GH₵540. Find the profit percentage.
Step 1: Calculate the profit.
Profit=SellingPrice−Cost Price
Profit=GH₵540−GH₵450
Profit=GH₵90
Step 2: Calculate the profit percentage.
Profit Percentage=CostPriceProfit×100%
Profit Percentage=GH₵450GH₵90×100%
Profit Percentage=0.2×100%
Profit Percentage=20%
The profit percentage is 20%.
20%
Q6.
i. Find the mode
Step 1: List the marks and count their frequencies:
42 (1), 55 (3), 50 (2), 48 (2), 62 (1), 38 (1), 60 (1), 45 (1)
Step 2: The mode is the mark that appears most frequently.
The mark 55 appears 3 times, which is more than any other mark.
The mode is 55.
55
ii. Find the range
Step 1: Identify the highest and lowest marks.
Highest mark = 62
Lowest mark = 38
Step 2: Calculate the range.
Range=Highestmark−Lowest mark
Range=62−38
Range=24
The range is 24.
24
b) A bag contains 4 red, 3 blue and 3 green balls. One ball is drawn at random.
Step 1: Find the total number of balls.
Total balls=4(red)+3(blue)+3(green)=10
i. Find the probability that it is: Blue
Step 2: The probability of drawing a blue ball is the number of blue balls divided by the total number of balls.
P(Blue)=TotalballsNumberofblueballs
P(Blue)=103
The probability of drawing a blue ball is 103.
103
ii. Not green
Step 2: The number of balls that are not green is the sum of red and blue balls.
Not green balls=4(red)+3(blue)=7
Step 3: The probability of drawing a ball that is not green is the number of non-green balls divided by the total number of balls.
P(Notgreen)=TotalballsNumberofnotgreenballs
P(Notgreen)=107
The probability of drawing a ball that is not green is 107.
107
Q7.
a) A taxi company charges a fixed fee of GH₵10 plus GH₵1.20 per kilometer. How much will a passenger pay for a trip of 15 km?
Step 1: Calculate the variable cost for 15 km.
Variable cost=15km×GH₵1.20/km
Variable cost=GH₵18.00
Step 2: Add the fixed fee to the variable cost.
Total cost=Fixedfee+Variable cost
Total cost=GH₵10.00+GH₵18.00
Total cost=GH₵28.00
A passenger will pay GH₵28.00 for a 15 km trip.
GH₵28.00
b) A rectangular field is 85 m long and 60 m wide. A farmer wants to put a fence around the field and also divide the field into 5 equal smaller plots by lines parallel to the shorter side.
i. What is the perimeter of the field?
Step 1: The formula for the perimeter of a rectangle is P=2(L+W).
P=2(85m+60m)
P=2(145m)
P=290 m
The perimeter of the field is 290 m.
290m
ii. How many metres of fencing will be needed altogether?
Step 1: The fencing around the field is its perimeter, which is 290 m.
Step 2: To divide the field into 5 equal smaller plots by lines parallel to the shorter side (60 m), 4 dividing lines are needed. Each dividing line will be 60 m long.
Length of dividing lines=4×60m=240 m
Step 3: Add the perimeter and the length of the dividing lines to find the total fencing needed.