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Grade 8 math · H.4 · Rate of change and initial value

Find the time when a target amount is reached

Write an equation: starting amount plus rate times time equals the target. Solve for time.

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  1. A hiker is 24 km from camp and walks toward it at 5 km every hour. After how many hours are there 4 km?

    Answer: 4

  2. A jar holds 32 coins and 3 more coins are added each week. After how many weeks are there 41 coins?

    Answer: 3

  3. A pool holds 8 L of water and a hose adds 3 L every minute. After how many minutes are there 29 L?

    Answer: 7

Tip: Write an equation: starting amount plus rate times time equals the target. Solve for time.

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