Answer:
6 hrs.
Explanation:
train time = plane time
x/55 = (1020-x)/285
Cross-multiply to get:
285x = 55(1020-x)
285x = 55*1020 - 55x
340x = 55*1020
x = 165 miles
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train time = 165/55 = 3 hrs
plane time = (1020-165)/285 = 3 hrs
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Total time = 6 hrs