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A train leaves north & travels at 85 kil per hr, another train leaves at the same time & travels south at 90 kil per hr. How long will it take before they are 700 kil apart?

"Train A travels north at 85 kilometers per hour"

After t hours, A has traveled 85t kilometers.

"Train B leaves at the same time and travels south at 90 kilometers per hour"

After t hours, B has traveled 90t kilometers.

Use the Pythagorean theorem to calculate the distance between A and B after t hours.

distance = √(85²t² + 90²t²)

= √(t²(85² + 90²)

= t√(85² + 90²)

≅ 123.8t

Solve for t

123.8t = 700

t ≅ 5.655 hours ≅ 5 hours and 39 minutes

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