What is the time $2$ hours and $15$ minutes after $6:15$$\mathrm{p}.\mathrm{m}$.$?$  $\mathrm{p}.\mathrm{m}$

Find the finishing date. The starting date is March $20$ and duration is $18$ days.

Find the starting date. Duration is $23$ days and the finishing date is January $15$.

Find the Duration. The starting date is September $11$ and the finishing date is October $9$.

Anjali eats dinner at $8:45$$\mathrm{p}.\mathrm{m}.$ If the time now is $7:50$$\mathrm{p}.\mathrm{m}.$, how much more time does she have until dinner$?$ 

Hari returned his library book on September $4$. If he had borrowed it a fortnight earlier, on what date was it issued by the library$?$(A fortnight is $14$ days or two weeks)

Thomas Alva Edison was born in $1847$. He invented the electric bulb. How old he was when he invented the electric bulb at $1879$?