Consider the C program below. (For space reasons, we are not checking error return codes, so assume that all functions return normally.) main() {
pid_t pid; int status;
printf("1");
if (fork() == 0) {
if (fork() == 0) {
printf("2");
}
}
else {
printf("3");
if (fork() == 0) {
printf("4");
exit(0);
}
else {
wait(&status);
printf("5");
}
}
printf("6");
return 0;
}

Answer the following questions. Note that incorrect answers count against you, so don't guess. You won't be penalized for selecting a blank answer, but you won't get points either.
a. Can 6 be printed before 5?
b. Will 5 always be printed after 4?
c. Can 6 be printed before 2?
d. Will 5 always be printed after 3?
e. Can 5 be printed before 2?

When creating a budget, log fixed expenses before income. after income. after savings. at the top.

Consider a slotted aloha system, where the time slot equals the fixed duration of each packet. assume that there are 4 stations a,b,c,d sharing the medium. (a) stations a,b,c,d receive one packet each from higher layers at times 1.3, 1.5, 2.6,5.7 respectively. show which transmissions take place when, according to the slottedaloha protocol; describe all transmissions until all four packets have been successful.when needed, each station has access to the following sequence of random number, provided by a random number generator and drawn uniformly between 0 and 1: (1) station a draws numbers: 0.31, 0.27, 0.78, 0.9, 0.9, 0.11, 0. (2) station b draws numbers: 0.45, 0.28, 0.11, 0.83, 0.37, 0.22, 0. (3)station c draws numbers: 0.1, 0.2, 0.3, 0.4, 0. (4) station d draws numbers: 0.36, 0.77, 0.9, 0.1, 0.1, 0.1, 0.1, 0. (b) in slotted aloha, a station transmits in each time slot with a given probability. what probabilities would you assign to each of the four stations so as to: (i) maximize the efficiency of the protocol? (ii) maximize fairness among the four stations? (c) will the efficiency increase or decrease if we modify slotted aloha as follows: (i) get rid of slots and allow stations to transmit immediately? (ii) implement carrier sensing? (iii) implement collision detection? (iv) implement collision avoidance?

When is a chart legend used a. all the time b. whenever you are comparing data that is the same c. whenever you are comparing multiple sets of data d. only for hand-drawn charts