The length, d, of Jamal's car is 4.72m, correct to 2 decimal places - OCR - GCSE Maths - Question 11 - 2020 - Paper 1

First, we determine the possible range for the distance and speed:

• Distance = 430 km, correct to 10 km, which implies a range of:

  • Minimum distance = 425 km
  • Maximum distance = 435 km

• Average speed = 57.3 km/h, correct to 1 decimal place, which implies:

  • Minimum speed = 57.25 km/h
  • Maximum speed = 57.35 km/h

Next, we calculate the shortest possible time using the maximum speed and the minimum distance:

$ext{Time} = \frac{\text{Distance}}{\text{Speed}}$

Substituting in the values:

$ext{Time} = \frac{425 ext{ km}}{57.35 ext{ km/h}} \approx 7.41 ext{ hours}$

To convert this to minutes:

$7.41 ext{ hours} \times 60 ext{ minutes/hour} \approx 444.6 ext{ minutes}$

Rounding to the nearest minute gives: 445 minutes.

Thus, the shortest possible time for Jamal's journey is 7 hours and 25 minutes (445 minutes).