Time measurement


There are two sand timers which can show 7 minutes and 4 minutes respectively. Measure time of 9 minutes using both.

SherlockHolmes Expert Asked on 11th August 2020 in Math Puzzles.
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  • 1 Answer(s)

    1. Start both the timers
    2. Once 4-min timer ends, flip it
    Elapsed Time – 4 minutes

    3. Once 7-min timer ends, flip it. There will be 1 min. remaining in 4-min timer.
    Elapsed Time – 7 minutes

    4. Once 4-min timer ends, there will be 6 min. remaining in 7-min timer. Flip 7-min timer
    Elapsed Time – 8 minutes

    5. When 7-min timer ends, total elapsed time will be 9 minutes.

    bhola99 Expert Answered on 11th August 2020.
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