Will you please provide me the previous year placement papers of Yahoo?????

Here I am providing you the previous year placement papers of Yahoo

1.What is the output of the following code?
x=0;y=1;
for(j=1;j<4;j++){
x=x+j;
y*=j;
}

2.There is a 200 miles long tunnel. one train enters the tunnel at a speed of 200mph while the other trains enter the tunnel in the opposite direction at a speed of 1000 mph. A bee travels at a speed of 1500 mph enters the tunnel goes to and back until it reaches the train. What is the distance covered by the bee when the two train collides (the bee survives)

3.List the two advantages of views.

4.Which layer is encryption and decryption done

5.What are the various modes used to send data over the network

6.Write a query to display the name of the students whose total marks is divisible by 25 (total marks may be 175, 200, 150...)

7.P(S1)
a++;

P(S2)
v++;

V(S2)

V(S1)

P-wait, V-signal, S1 and S2 are semaphores. Consider two threads running. Is there a deadlock .If yes in which situation does the deadlock occur.

8.How do you find the port number of the remote host?

9. (Date; who)>logfile

Date; who>logfile
What is the difference between the two statements.

10.How do you find the machine MAC address

11.Write the set operators that are used for select.

12.Write a single command to find and delete all the files that are older than 1 day (modification time)

13.A is a 3*4 matrix and B is 4*5 matrix. What is the number of additions and multiplications performed to obtain the resultant matrix

14.What is the output
#!/bin/perl
kill -0 pid

15.#!/bin/perl
echo $_

16. #!/bin/perl
kill $$
echo "hello world"

17.List different schema/database objects

18.Randomization is good for which algorithm(quick sort, heap sort, selection sort, hashed table, ...)

19.Descride the language in the following regular expression (a*a) b+b

20.In an I-node what is not there (file type, file name, size, owner)

21.If the probability of work done by three persons are 1/3, 2/5, 5/12. Then what is the probability that the work is completed.

22.Given Id, author, creation time, size, links, web page, description
Bring it in 2nd normal form

23.Consider a heap containing numbers 10, 20, 30, 40, 80, 60, 70 such that numbers are in ascending order from the leaf to the root. If 25 is to be inserted what is the position.
(A[1], A[2], A[3], A[4])

24. #!/bin/perl
var=///
aaaa
echo ‘$var’

25.Krishna tosses a one-rupee coin and a rupee coin. He announces that one is head. But the result is not announced. What is the probability that the other coin is head?

26. In database sort the student id and the course id for each student. Which is the best possible solution?
- Sort the student id using a stable algorithm and then sort the course id using unstable algorithm
- Sort the student id using a unstable algorithm and then sort the course id using stable algorithm
- Sort the course id using a stable algorithm and then sort the student id using unstable algorithm
- Sort the course id using a unstable algorithm and then sort the student id using unstable algorithm