Renu can do a piece of work in 5 days, but with the help of her friend Suma , she can do it in 4 days. In what time Suma can do it alone?
Choose the correct choice from the following answers.
A) 10 B) 12 C) 14 D) 15 E) 20
Renuâ€™s one dayâ€™s work = 1/5   Sumaâ€™s one dayâ€™s work = 1/4 - 1/5 = 1/20   Suma can do it alone in 20 days.   ANSW20R:20
<result>E</result>
Renu can do a piece of work in 5 days, but with the help of her friend Suma , she can do it in 4 days. In what time Suma can do it alone?