At 4 miles per hour, it takes exactly one hour for Abe to walk to school in a blinding blizzard. How many minutes would it take for him if he were to walk at 5 miles per hour?

At 4 miles per hour, it takes exactly one hour for Abe to walk to school in a blinding blizzard. How many minutes would it take for him if he were to walk at 5 miles per hour?

• A. 30 minutes
• B. 40 minutes
• C. 60 minutes
• D. 48 minutes

Answer: (D)

Key idea: for a fixed distance, time is inversely proportional to speed. Time equals distance divided by speed. Abe covers 4 miles in one hour at 4 mph, so the distance to school is 4 miles. At 5 mph, the time needed is 4 miles ÷ 5 mph = 0.8 hours. Convert to minutes: 0.8 × 60 = 48 minutes. So it would take 48 minutes. The blizzard is just extra context; the distance doesn’t change.

Key idea: for a fixed distance, time is inversely proportional to speed. Time equals distance divided by speed.

Abe covers 4 miles in one hour at 4 mph, so the distance to school is 4 miles. At 5 mph, the time needed is 4 miles ÷ 5 mph = 0.8 hours. Convert to minutes: 0.8 × 60 = 48 minutes. So it would take 48 minutes. The blizzard is just extra context; the distance doesn’t change.