Difficulty: Easy
Correct Answer: 6 h
Explanation:
Introduction / Context:
Time varies inversely with speed for a fixed distance. Reducing speed to 3/4 of usual increases time by a factor of 4/3. The difference between the stretched time and the original time is given as 2 hours.
Given Data / Assumptions:
Concept / Approach:
Set (4/3)t − t = 2 and solve for t to find the usual-time value directly.
Step-by-Step Solution:
Verification / Alternative check:
At reduced speed, time = (4/3)*6 = 8 hours, which is 2 hours more than 6 hours—matches the statement.
Why Other Options Are Wrong:
4, 5, 7, 9 hours would not make the time difference exactly 2 hours under a 3/4 speed reduction.
Common Pitfalls:
Using 3/4 on time instead of on speed; forgetting that time scales as the reciprocal of speed.
Final Answer:
6 h
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