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Course: Class 8 > Unit 11

Lesson 2: Direct and Inverse proportions 11.2
Math
Class 8
Direct and Inverse proportions
Direct and Inverse proportions 11.2
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Word problems on direct and inverse proportion

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Problem

My phone battery lasts for 20 hours when fully charged. The duration that the battery lasts is proportional to its percentage charge.
How long will the battery last if it is 30% charged?
  • Your answer should be
  • an integer, like 6
  • a simplified proper fraction, like 3/5
  • a simplified improper fraction, like 7/4
  • a mixed number, like 1 3/4
  • an exact decimal, like 0.75
  • a multiple of pi, like 12 pi or 2/3 pi
hours