Bank accounts $a,b,c$ contain values $,,,$ respectively. Concurrent transfers of certain amounts from accounts $a,b$

to $c$ are carried out by the following programs $(ra,rb$ are working variables$)$:

transfer of $200$ from account a to account $c$ :

transfer of $50$ from account $b$ to account $c$ :

ABORT else $],[\{b$:$=b-50$;$rb$:$=c$;$rb$:$=rb+50$;$c$:$=rb\}]|$

What may be the balance of the $c$ account after transfers when:

update $c$ is not protected by a critical section? List all possible values of $c.$

update $c$ is protected then $c=$dots

In the Cristian's clock synchronization method, the client sends an order to the time server and receives a

response T$.4$ milliseconds elapsed from the order to receiving the response, and the server used $2$ millisecond to

prepare and send the response. By how many milliseconds does the client increase the received time T to

synchronize its local time with the server time?

Here is an image of the communication between the three processes according to their local clocks:

Which $xy$ communications require time compensation so that the implication occurs: $xy=>C(x)C(y)$ for any

events $x,y,$ in the above diagram, where $C(x),C(y)$ are the compensated time stamps of these events.