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Pipes and Cisterns

Quantitative Aptitude · Maths Bookwise · Work & Motion

Useful for: SSC CGL

BOOK-GUIDED ORIGINAL SSC MATHS PRACTICE — Pipes and Cisterns

FOUNDATION

Net filling rate = inlet rate − outlet rate.

METHOD

Identify the quantities given, choose the exact relationship, calculate in the same unit, then check the answer against the question.

WORKED EXAMPLE 1

A tap fills a tank in 405 hours; a drain empties it in 810 hours. Both open: when full?

Net rate = 1/405−1/810=1/810 tank/hour; time = 810 hours.

WORKED EXAMPLE 2

A tap fills a tank in 1059 hours; a drain empties it in 2118 hours. Both open: when full?

Net rate = 1/1059−1/2118=1/2118 tank/hour; time = 2118 hours.

IMPORTANT EXCEPTION / COMMON TRAP

Subtract the leak or emptying pipe.

QUICK REVISION

Net filling rate = inlet rate − outlet rate.

SEE MORE: https://study.kundali-iq.com/ssc-maths/pipes/

For complete timed maths practice, use SSC CGL Test Series → New Maths 100 Mixed Sets or Chapter-wise sets. These are independent original questions, not copied previous-year questions.

Practice MCQs

  1. A tap fills a tank in 405 hours; a drain empties it in 810 hours. Both open: when full?

    1. 864
    2. 810
    3. 756
    4. 918

    Read chapter notes · Similar questions

    Show answer

    Answer: (b) 810. Net rate = 1/405−1/810=1/810 tank/hour; time = 810 hours.

  2. A tap fills a tank in 1059 hours; a drain empties it in 2118 hours. Both open: when full?

    1. 2259
    2. 2118
    3. 2400
    4. 1977

    Read chapter notes · Similar questions

    Show answer

    Answer: (b) 2118. Net rate = 1/1059−1/2118=1/2118 tank/hour; time = 2118 hours.

  3. A tap fills a tank in 129 hours; a drain empties it in 258 hours. Both open: when full?

    1. 241
    2. 258
    3. 275
    4. 292

    Read chapter notes · Similar questions

    Show answer

    Answer: (b) 258. Net rate = 1/129−1/258=1/258 tank/hour; time = 258 hours.

  4. A tap fills a tank in 249 hours; a drain empties it in 498 hours. Both open: when full?

    1. 465
    2. 531
    3. 498
    4. 564

    Read chapter notes · Similar questions

    Show answer

    Answer: (c) 498. Net rate = 1/249−1/498=1/498 tank/hour; time = 498 hours.

  5. One pipe fills a tank in 12 hours and another in 18 hours. Both working together, how many hours are needed

    1. 8 hours
    2. 6 hours
    3. 36/5 hours
    4. 15/2 hours

    Read chapter notes · Similar questions

    Show answer

    Answer: (c) 36/5 hours. Together their rate is 1/12 + 1/18 = 5/36 tank/hour, so time = 36/5 hours.

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Notes and questions are written by Kundali IQ for practice. They are not official papers; always check the latest official notification for the syllabus and pattern.