Aptitude Discussion

Q. |
$A$ and $B$ together can complete a piece of work in 35 days while $A$ alone can complete the same work in 60 days. $B$ alone will be able to complete the same working in: |

✖ A. |
74 Days |

✖ B. |
80 Days |

✔ C. |
84 Days |

✖ D. |
90 Days |

**Solution:**

Option(**C**) is correct

__Formula Used:__

**Subtraction of fraction**

\(\dfrac{a}{b}-\dfrac{c}{d}=\dfrac{ad-cb}{bd}\)

$A$ and $B$ finish one work with company = $35$ days

$(A + B)’$s one day’s work = \(\dfrac{1}{35}\)

$A$ alone finish the same work = $60$ days

$A’$s one day’s work = \(\dfrac{1}{60}\)

$B’$s one day’s work = $(A + B)’$s one day’s work - $A’$s one day’s work

\(\dfrac{1}{35}-\dfrac{1}{60}=\dfrac{1}{84}\)

Hence $B$ alone can complete the work in **84 days**