Multiple choice

Each of given questions consists of a question followed by informations in three statements. You have to study the question and the statements and decide that information in which of the statement(s) is/are necessary to answer the question. P,Q and R working together can complete a work in how many days? Statement I: P can complete half of the work in 4 days and Q can complete one third of the work in 2 days. Statement II: The ratio of their efficiencies of P, Q and R is 3:4:6 respectively. Statement III: R can do as much work in 2 days as Q can do in 6 days.

  1. Any two

  2. I and II

  3. I and (II or III)

  4. Only I

  5. None of these
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Statement I gives P: 1/2 work in 4 days (rate=1/8 per day), Q: 1/3 work in 2 days (rate=1/6 per day). Statement II gives P:Q:R efficiency ratio as 3:4:6, so R=1.5×Q=1/4 per day. Statement III gives R's 2-day work equals Q's 6-day work, so R=3×Q=1/2 per day. Statements II and III give contradictory values for R. Need I plus either II or III (but not both).

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