The travel problem is complicated, so you must (pay attention to) draw a line diagram, observe, carefully observe, think flexibly, pay attention to changing some sentences (some sentences hide certain conditions), then list the formulas (or equations) according to the formulas, and check the answers in the questions after you finish. The specific formula is as follows: basic formula: distance = speed × time; Distance ÷ time = speed; Distance/speed = time

Key question: determine the position in the journey.

Meeting problem: speed sum × meeting time = meeting distance (please write other formulas)

Meeting problem: (straight line): distance of A+distance of B = total distance.

Meeting problem: (ring): the distance of a+the distance of b = the circumference of the ring.

Follow-up question: Pursuit time = distance difference ÷ speed difference (write other formulas)

Follow-up questions: (straight line): distance difference = chaser distance-chased distance = speed difference x catching time.

Follow-up question: (circle): fast distance-slow distance = curve perimeter

Train crossing the bridge: the key is to determine the moving distance of the object, refer to the above formula.

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