Time and Work Questions

$\text{C}$ and $\text{B}$ can do a work in $18\text{ days}$ and $24\text{ days}$ respectively. They worked together for $8\text{ days}$ and then $\text{C}$ left. In how many days did $\text{B}$ finish the remaining work?

$\text{A}$ and $\text{B}$ each can do a work in $75\text{ days}$. They began the work together but $\text{A}$ left after some time and $\text{B}$ completed the remaining work in $23\text{ days}$. After how many days of the start of the work did $\text{A}$ leave?