$A$ 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 $Rs.$)

$A$ and $B$ can do a work in $12$ days,$B$ and $C$ in $15$ days,and $C$ and $A$ in $20$ days. If $A, B,$ and $C$ work together,they will complete the work in (in days):

$A$ and $B$ together can do a piece of work in $30$ days. $B$ and $C$ together can do it in $20$ days. $A$ starts the work and works on it for $5$ days,then $B$ takes over and works for $15$ days. Finally,$C$ finishes the work in $18$ days. The number of days in which $C$ alone can do the work is (in days):

To complete a work,$A$ takes $50 \%$ more time than $B$. If together they take $18 \text{ days}$ to complete the work,how much time shall $B$ take to do it? (in days)

$12$ men can complete a piece of work in $4$ days,while $15$ women can complete the same work in $4$ days. $6$ men start working on the job and after working for $2$ days,all of them stopped working. How many women should be put on the job to complete the remaining work,if it is to be completed in $3$ days?

Rohan and Mohit can build a wall in $8 \, days$,Mohit and Vikas can build the same wall in $10 \, days$,and Vikas and Rohan can build the same in $12 \, days$. In how many days can all three complete the same wall while working together?