For which type of vehicle was there the greatest decrease in road accidents from the 1930s to the 1990s, and was this decrease by greater or less than 50% of the original figure?

Steps to Solve

1. Identify the accident numbers for each vehicle type

   From the graph for the year 1930s, note the number of accidents for each type of vehicle:

   • Motorcycle: 150
   • Sports car: 30
   • SUV: 60
   • Bus: 80

2. Identify the accident numbers for each vehicle type in the 1990s

   From the graph, note the number of accidents for each type of vehicle in 1990s:

   • Motorcycle: 50
   • Sports car: 10
   • SUV: 20
   • Bus: 30

3. Calculate the absolute reduction in accidents for each vehicle type

   Subtract the 1990s figure from the 1930s figure for each vehicle type:

   • Motorcycle: $150 - 50 = 100$
   • Sports car: $30 - 10 = 20$
   • SUV: $60 - 20 = 40$
   • Bus: $80 - 30 = 50$

4. Determine the percentage reduction for each vehicle type

   To find the percentage reduction, use the formula:

   $$\text{Percentage Reduction} = \left( \frac{\text{Reduction}}{\text{Original}} \right) \times 100$$

   Calculate for each type:

   • Motorcycle: $$\frac{100}{150} \times 100 = \frac{10000}{150} \approx 66.67%$$
   • Sports car: $$\frac{20}{30} \times 100 = \frac{2000}{30} \approx 66.67%$$
   • SUV: $$\frac{40}{60} \times 100 = \frac{4000}{60} \approx 66.67%$$
   • Bus: $$\frac{50}{80} \times 100 = \frac{5000}{80} \approx 62.5%$$

5. Analyze which vehicle type had the greatest decrease and if it was more or less than 50%

   All calculated percentages are greater than 50%. Since the motorcycle had the largest reduction percentage of approximately 66.67%, it is the answer.