Bob will need to travell 18 miles more to complete his trip if he had travelled 90 miles before.
The concept that will be used is the concept of percentage.
From the question, 83 1/3% of his journey has completed, then we need to calculate this and convert it to miles, which =0.833
The total distance will now be 90miles/0.833
= 108 miles
The remaining journey to complete his journey will now be [ (108) - (90)]= 18miles.
Hence, Bob will need to travel 18miles more.
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