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Word problemsArithmeticMiddle schoolabout 1:28

A shirt costs $40 and is 25% off. What is the sale price?: animated lesson

A narrated, step-by-step word problems video lesson with captions. Final answer: New price = 30 (the discount is 10).

Video with a synthetic English voice and captions. Pick another language for subtitles in that language, or open the interactive version.

Video narrated by a synthetic voice (Piper TTS, en_US-ljspeech-high voice (LJ Speech dataset, public domain)); the steps come from our maths engine and the answer was checked independently. Download MP4 (0.5 MB) · Captions (WebVTT)

Steps on screen

  1. 1. The problem
    Worked example
    A shirt costs 40 and is 25% off. What is the sale price?
  2. 2. Steps, part 1
    1. Read the problem
    2. Identify the known values
    3. new=old×(1+p100)\text{new} = \text{old}\times\left(1 + \frac{p}{100}\right)
      Write the equation
    4. Solve for new
  3. 3. Steps, part 2
    1. Result
  4. 4. The answer
    New price = 30 (the discount is 10)\text{New price = 30 (the discount is 10)}

    new = 30

  5. 5. Check
    • Substituting new = 30 back into new = old × (1 + p/100) balances both sides ✓

Transcript

The problem. Here is the problem: A shirt costs 40 and is 25 percent off. What is the sale price? The original price is 40 and it decreases by 25 percent, so the percent change is negative 25 percent. Percent increase or decrease; old equals 40, p equals negative 25 percent; solve for new.

Steps, part 1. Read the problem. The original price is 40 and it decreases by 25 percent, so the percent change is negative 25 percent. Identify the known values. Percent increase or decrease. Known: old equals 40, p equals negative 25 percent. Unknown: new value (new). Write the equation. new equals old times (1 plus p/100). Solve for new. new equals 40 times (1 plus negative 0.25).

Steps, part 2. Result. new equals 30.

The answer. So the answer is New price equals 30 (the discount is 10). Substitute the known values into new equals old times (1 plus p/100) and isolate new. Keep units consistent (for example miles, miles per hour and hours).

Check. Substituting new equals 30 back into new equals old times (1 plus p/100) balances both sides, which checks out.

About word problems

Turn everyday situations about prices, speed, ages and interest into equations and solve them.

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A shirt costs $40 and is 25% off. What is the sale price?