$A$ is $4$ times as fast as $B$ and is,therefore,able to complete a work in $45$ $days$ less than $B$. $A$ and $B$,working together,can complete the work in (in $days$)

$A$ man and a boy received $Rs. 800$ as wages for $5$ days for the work they did together. The man's efficiency in the work was three times that of the boy. What are the daily wages of the boy? (in $Rs.$)

$A$ daily-wage labourer was engaged for a certain number of days for $Rs. 5,750$ but being absent on some days he was paid only $Rs. 5,000$. What was his maximum possible daily wage? (in $Rs.$)

$20$ men can complete a piece of work in $16$ days. After $5$ days from the start of the work,some men left. If the remaining work was completed by the remaining men in $18 \frac{1}{3}$ days,how many men left after $5$ days from the start of the work?

If $A, B,$ and $C$ can complete a work in $6$ days together. If $A$ can work twice as fast as $B$ and thrice as fast as $C$,then the number of days $C$ alone can complete the work is (in days):

$A$ and $B$ can complete a piece of work in $45$ and $40$ days,respectively. They began the work together,but $A$ leaves after some days and $B$ completed the remaining work in $23$ days. After how many days did $A$ leave?