Secondary 1 Other Practice Paper 1

TuitionGoWhere Practice Paper - Other Secondary 1 - Answer Key

Total Marks: 50

Section A: Short Answer Questions [20 marks]

1. Simplify the ratio 2.8 : 7/10 to its simplest form. [2] Answer: 4 : 1 Working: 2.8 : 7/10 = 14/5 : 7/10 = 28/10 : 7/10 = 28 : 7 = 4 : 1 Marking: 1 mark for converting to common form, 1 mark for correct simplification

2. Express 45 minutes as a fraction of 2 hours in its simplest form. [2] Answer: 3/8 Working: 2 hours = 120 minutes. Fraction = 45/120 = 3/8 Marking: 1 mark for converting 2 hours to minutes, 1 mark for correct simplification

3. A school bag costs $48 before GST. If GST is 7**Answer:**$51.36 Working: GST = 7% of $48 =$3.36. Total = $48 +$3.36 = $51.36 Marking: 1 mark for calculating GST, 1 mark for correct total

4. Calculate the mean number of books borrowed per day. [2] Answer: 48 books Working: Total = 45 + 52 + 38 + 61 + 44 = 240. Mean = 240 ÷ 5 = 48 Marking: 1 mark for correct total, 1 mark for correct mean

5. Convert 72 km/h to m/s. [2] Answer: 20 m/s Working: 72 km/h = 72 × 1000/3600 = 72000/3600 = 20 m/s Marking: 1 mark for correct conversion method, 1 mark for correct answer

6. How many students chose Mathematics? [2] Answer: 72 students Working: 3/5 of 120 = 3/5 × 120 = 72 students Marking: 1 mark for method, 1 mark for correct answer

7. Calculate the perimeter of the room. [2] Answer: 20.0 m Working: Perimeter = 2(5.8 + 4.2) = 2(10.0) = 20.0 m Marking: 1 mark for correct formula, 1 mark for correct calculation

8. Express (2y + 7) seconds in minutes. [2] Answer: (2y + 7)/60 minutes Marking: 2 marks for correct algebraic expression

9. Explain one way 3D effects could be misleading. [2] Answer: The 3D effects make sections at the front appear larger than they actually are, distorting the true proportions of the data. Marking: 1 mark for identifying the issue, 1 mark for explaining the consequence

10. Simplify the ratio 1 1/4 : 2/3 : 1.5 [2] Answer: 15 : 8 : 18 Working: 5/4 : 2/3 : 3/2. Multiply by 12: 15 : 8 : 18 Marking: 1 mark for converting to improper fractions, 1 mark for correct simplification

Section B: Structured Questions [30 marks]

11. Singapore Botanic Gardens visitors

(a) Percentage increase from 2018 to 2019. [2] Answer: 10% Working: Increase = 4,620 - 4,200 = 420. Percentage = (420 ÷ 4,200) × 100% = 10% Marking: 1 mark for finding increase, 1 mark for correct percentage

(b) Percentage decrease from 2019 to 2020. [2] Answer: 54.55% Working: Decrease = 4,620 - 2,100 = 2,520. Percentage = (2,520 ÷ 4,620) × 100% = 54.55% Marking: 1 mark for finding decrease, 1 mark for correct percentage

(c) Reason for decrease in 2020. [1] Answer: COVID-19 pandemic / Circuit breaker measures / Travel restrictions Marking: 1 mark for any reasonable explanation related to pandemic

(d) Mean visitors per year. [2] Answer: 3,444 thousand visitors Working: Total = 4,200 + 4,620 + 2,100 + 2,520 + 3,780 = 17,220. Mean = 17,220 ÷ 5 = 3,444 Marking: 1 mark for correct total, 1 mark for correct mean

12. School canteen meal deals

(a) Discounted price of Set B. [2] Answer: $4.42 **Working:** Discount = 15$5.20 = $0.78. Discounted price =$5.20 - $0.78 =$4.42 Marking: 1 mark for calculating discount, 1 mark for final price

(b) Total revenue. [3] Answer: $1,358.40 **Working:** Set A:$4.50 × 0.85 = $3.825 × 180 =$688.50 Set B: $5.20 × 0.85 =$4.42 × 120 = $530.40 Set C:$6.80 × 0.85 = $5.78 × 80 =$462.40 Total = $688.50 +$530.40 + $462.40 =$1,681.30 Marking: 1 mark for each set calculation, 1 mark for correct total

(c) Original price of Set D. [3] Answer: $7.06 **Working:** Let original price = x. After 15$6.00. x = $6.00 ÷ 0.85 =$7.06 Marking: 1 mark for setting up equation, 1 mark for method, 1 mark for correct answer

13. Cyclists problem

(a) Combined speed. [1] Answer: 24 km/h Marking: 1 mark for adding speeds correctly

(b) Time to meet. [3] Answer: 1 hour 0 minutes Working: Time = 24 km ÷ 24 km/h = 1 hour Marking: 1 mark for correct method, 1 mark for calculation, 1 mark for expressing in hours and minutes

(c) Distance Priya travels. [2] Answer: 16 km Working: Distance = 16 km/h × 1 hour = 16 km Marking: 1 mark for method, 1 mark for correct answer

(d) Effect of David's head start. [2] Answer: No, they would not meet at the same point. David would be closer to Priya's starting point because he had extra time to travel towards her. Working: With 15 minutes (0.25 hours) head start, David travels an extra 8 × 0.25 = 2 km before Priya starts. Marking: 1 mark for correct conclusion, 1 mark for reasonable explanation

14. Transport survey

(a) Students who prefer bus. [2] Answer: 90 students Working: 45% of 200 = 0.45 × 200 = 90 students Marking: 1 mark for method, 1 mark for correct answer

(b) Ratio of MRT to walking. [2] Answer: 2 : 1 Working: MRT: 30%, Walking: 15%. Ratio = 30 : 15 = 2 : 1 Marking: 1 mark for identifying percentages, 1 mark for correct simplification

(c) Effect of bright colors and 3D. [2] Answer: Bright colors might draw attention to certain sections making them seem more important, while 3D effects can make some sections appear larger than they actually are, distorting the true proportions. Marking: 1 mark for identifying color issue, 1 mark for identifying 3D distortion

(d) Improvement suggestion. [1] Answer: Use a simple 2D pie chart with neutral colors / Use a bar chart / Include data labels with exact percentages Marking: 1 mark for any reasonable improvement suggestion

Total: 50 marks