Practicing Success
To do a certain work, A and B work on alternate days with B beginning the work on the first day. A alone can complete the same work in 24 days. If the work gets completed in $11\frac{1}{3}$ days. then B alone can complete $\frac{7}{9}$th part of the original work in: |
$4\frac{1}{2}$ days 6 days $5\frac{1}{2}$ days 4 days |
6 days |
Given: Time taken by A to finish a task alone = 24 days Calculation: Let the total work be = 1 A alone can finish the task in 24 days ⇒ A's one-day work = \(\frac{1}{24}\) A and B complete the whole task in = \( {11}_{3 }^{ 1} \) days A and B work on alternate days, with B beginning so, we can say B will work only 6 days ⇒ A will work only \( {11}_{3 }^{ 1} \) - 6 = \( {5}_{3 }^{ 1} \) days If A's one day work = \(\frac{1}{24}\)of work A completes in 1 day ⇒ A's \( {5}_{3 }^{ 1} \) days work = \(\frac{1}{24}\) × \( {5}_{3 }^{ 1} \) = \(\frac{1}{24}\) × \(\frac{16}{3}\) ⇒ \(\frac{2}{9}\) Remaining work = 1 - \(\frac{2}{9}\) = \(\frac{7}{9}\) Therefore, B does the \(\frac{7}{9}\)th part of the work in 6 days.
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