$A, B$ and $C$ can complete a work in $2 \, h$. If $A$ does the job alone in $6 \, h$ and $B$ in $5 \, h$,how long will it take for $C$ to finish the job alone? (in $h$)

Sakshi can do a piece of work in $20$ days. Tanya is $25\%$ more efficient than Sakshi. The number of days taken by Tanya to do the same piece of work is

$4$ men and $6$ women together can complete a work in $8$ days,while $3$ men and $7$ women together can complete it in $10$ days. $20$ women working together will complete it in (in days):

$18$ boys can do a piece of work in $24$ days. In how many days can $27$ boys do the same work?

$A$ is $30\%$ more efficient than $B.$ How much time will they,working together,take to complete a job which $A$ alone could have done in $23$ days? (in days)

$A$ and $B$ together can complete a task in $20$ days. $B$ and $C$ together can complete the same task in $30$ days. $A$ and $C$ together can complete the same task in $40$ days. What is the ratio of the number of days taken by $A$ when completing the same task alone to the number of days taken by $C$ when completing the same task alone?