Two typists of varying skills can do a typing jobin6 minutesifthey work together.Ifthe first typist typed alone for 4 minutes and then the second typist typed alone for 6 minutes, they would be left with 1/5 of the whole work.Howmany minutes would it take the slower typist to complete the typing job working alone?

Working efficiency of both typist together = 100/6 = 16.66%

Let the efficiency of first typist be x and second typist be (16.66 –x)

First typist for 4 minute + second tyoistfor 6 minute = 80% work

⇒4x + (16.66 –x) X 6 = 80%

⇒4x + 100% -6x = 80%,

⇒x = 10%

First typist typed 10% per minute, second typst typed (16.66 –10) = 6.66% per minute

Slowest is second typist complete whole job in 100/6.66 = 15.01 = 15 minute