MBApyq

Humans and Robots Work Rates

CAT 2019 Slot 1 · Quantitative Ability · Easy · Work and Time

This is an easy Quantitative Ability question from the CAT 2019 Slot 1 paper. It tests Work and Time. The full answer key and a step-by-step explanation are below — try it yourself first, then reveal the solution.

All CAT 2019 Slot 1 questionsMore Work and Time questionsAll CAT QA

Humans and robots can both perform a job but at different efficiencies. Fifteen humans and five robots working together take thirty days to finish the job, whereas five humans and fifteen robots working together take sixty days to finish it. How many days will fifteen humans working together (without any robot) take to finish it?

  1. A.

    40

  2. B.

    32

  3. C.

    36

  4. D.

    45

Answer

B

Explanation

Let daily rate of human = hh, robot = rr. Total work W=30(15h+5r)=450h+150rW = 30(15h + 5r) = 450h + 150r. Also W=60(5h+15r)=300h+900rW = 60(5h + 15r) = 300h + 900r. 450h+150r=300h+900r⇒150h=750r⇒h=5r450h + 150r = 300h + 900r \Rightarrow 150h = 750r \Rightarrow h = 5r. Total work W=450h+150(h/5)=450h+30h=480hW = 450h + 150(h/5) = 450h + 30h = 480h. Time taken by 15 humans alone = 480h15h=32\frac{480h}{15h} = 32 days.

Related Work and Time questions

Practise this under exam conditions

Sign in to solve it with a live timer, the on-screen CAT calculator, and streak and accuracy tracking across every question you attempt.

Solve in the workspace