A student investigated the effect of exercise on breathing rate. The student's breathing rate at rest was 12 breaths per minute. After running for 5 minutes, the breathing rate increased to 36 breaths per minute. What is the percentage increase in breathing rate?

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Question

A student investigated the effect of exercise on breathing rate. The student's breathing rate at rest was 12 breaths per minute. After running for 5 minutes, the breathing rate increased to 36 breaths per minute. What is the percentage increase in breathing rate?

Accepted Answer

200% — Award 1 mark for correct calculation. Method: (36 - 12) / 12 × 100 = 24/12 × 100 = 200%. A is incorrect — this is the absolute increase, not the percentage. B is incorrect — this would be (36-12)/36 × 100, using the wrong denominator. D is incorrect — this is 36/12 × 100, which does not subtract the original value.

Answer

300%

Answer

24%

Answer

200%

Answer

67%

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