Anshu, Swati and Rajni can finish a work in 4 days if they work together. However, Anshu alone will take 9 days to complete the work, and Swati alone will complete the work in 12 days. How many days will Rajni alone take to complete the work ?
Answer & explanation
Correct answer: option 1
Anshu + Swati + Rajni = 4 days
Anshu = 9 days
Swati = 12 days
As, Anshu + Swati + Rajni = 9
Anshu = 4
Swati = 3,
Simplifying it, we get that efficiency of RAJNI is 2.
⇒ Hence, Time taken by Rajni to complete total work alone is = \(\frac{36}{2}\) = 18 days.