Question

Renu can do a piece of work in 6 days but with the help of her friend Suma she can do it in 4 days. in what time can Suma do it alone ? ​

Answer 1

Answer:

the amount of work as LCM(6,4)=12

So rate of Renu is 12/6 = 2

And combined rate of Renu and Suma is 12/4 = 3

Thus rate of Suma is 3–2 = 1

Hence, Suma can do the work alone (at the rate of 1) in 12/1 = 12 days

Answer 2

Time taken by Suma do  the  work alone is 12 days.

Step-by-step explanation:

Given:

Renu  do a piece of work in 6 days.

With help  of friend Suma she can do it in 4 days.

To Find:

Time taken by Suma do  the  work alone.

Formula Used:

If P can do a piece of work in q days, then A's 1 day's work =1/q

If P's 1 day's work =1/q,then A can finish the work in q  days.

Solution:

As given - Renu  do a piece of work in 6 days.

           Then,   Renu’s one day’s  work $=\frac{1}{6}$

As given- With help  of friend Suma,  she can do it in 4 days.

  Then ,   Renu’s and Suma’s one day’s  work $=\frac{1}{4}$

Suma’s one day’s  work = Renu’s and Suma’s one day’s  work- Renu’s one day’s  work

                                          $=\frac{1}{4} - \frac{1}{6}$          

                                          $=\frac{6-4}{24}$

    Suma’s one day’s  work $=\frac{1}{12}$

Then, time taken by Suma do  the  work alone is 12 days.

Thus, time taken by Suma do  the  work alone  is 12 days.