WEBVTT

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Here is the problem: A car travels 150 miles in 3 hours. What is its average speed?

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Distance 150 miles, time 3 hours; the rate is unknown. Distance equals rate times time; d equals 150, t equals 3; solve for r.

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Read the problem. Distance 150 miles, time 3 hours; the rate is unknown.

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Identify the known values. Distance equals rate times time. Known: d equals 150, t equals 3. Unknown: rate (speed) (r).

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Write the equation. d equals r times t.

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Solve for r. Divide both sides by t: r equals d / t.

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Continue. r equals 150 over 3.

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Result. r equals 50.

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So the answer is Rate (speed) equals 50 miles per hour.

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Substitute the known values into d equals r times t and isolate r. Keep units consistent (for example miles, miles per hour and hours).

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Substituting r equals 50 back into d equals r times t balances both sides, which checks out.