Question

A and B together can finish a piece of work in 12 days . If A alone can finish the same work in 20 days, in how many days B alone can finish it

Answer 1

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☞ B alone will get the work done in 30 days

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$\huge\sf\blue{Given}$

✭ A and B can finish a piece of work in 12 days

✭ A alone can finish the same work in 20 days

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✭ Time taken by B to complete the same work?

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$\bullet\:\underline{\textsf{As Per the Question}}$

☯ If A and B can finish the work in 12 days,then,

➝ $\sf 1 \ day = \dfrac{1}{12}$ of the work

Now the time that A will take to finish the work in a day

»» $\sf 1 \ day = \dfrac{1}{20}$ of the work

So then the amount of work that can be done by B will be,

➳ $\sf 1 \ day = Total \ Work - Work \ by \ A$

➳ $\sf 1 \ day = \dfrac{1}{12} - \dfrac{1}{20}$

➳ $\sf\red{\dfrac{1}{30}}$

Finally the time that B will take to complete his work alone will be,

➢ $\sf \dfrac{1}{30}$ of the work = 1 day

➢ $\sf 1\times 30$

➢ $\sf\orange{B =30 \ days}$

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