To find out Tim's average speed, let's first determine how long Hunk took to complete the 550 km and then figure out how long Tim took.
1. Calculate Hunk's travel time:
Distance = Speed × Time
Given that Hunk's average speed is 90 km/hour, and the distance he traveled was 550 km:
Time taken by Hunk = Distance/Speed
= 550 km ÷ 90 km/hour
= 6.1111 hours
= 6 hours + 0.1111(60 minutes)
= 6 hours + 6.666 minutes
= 6 hours + 6 minutes and 40 seconds
2. Calculate Tim's travel time:
Tim completed the same distance in 1 hour and 30 minutes less time than Hunk:
Time taken by Tim = 6 hours + 6 minutes and 40 seconds - 1 hour 30 minutes
= 4 hours + 36 minutes and 40 seconds
= 4.6111 hours (when converted to a decimal).
3. Calculate Tim's average speed:
Distance = Speed × Time
Given that Tim also traveled 550 km, and we have found his time to be 4.6111 hours:
Speed of Tim = Distance/Time
= 550 km ÷ 4.6111 hours
= 119.25 km/hour (rounded to two decimal places)
So, Tim's average speed for the whole journey was approximately 119.25 km/hour.