MATHS: PROBABILITY

A few questions in probability....


Q. 1. Two dice are rolled once. Find the probability that:
1. the numbers on two dice are different
2. the total of numbers on the two dice is at least 4
Q. 2. A pair of dice is tossed twice. If the random variable X is defined as the number of doublets, find the probability distribution of X.


Q. 3. In a factory, which manufactures nuts, machines A, B and C manufacture respectively 25%, 35% and 40% of nuts. Of their output 5, 4 and 2 per cent respectively are defective nuts. A nut is drawn at random from the product and is found to be defective. Find the probability that it is manufactured by machine B.


Q. 4. If the mean and variance of the binomial distribution are respectively 9 and 6, find the distribution.


Q. 5.8% of people in a group are left handed. What is the probability that 2 or more of a random sample of 25 from the group are left handed?

CHEMISTRY: CONVERSIONS

Convert the following:


1. phenol to salicylic acid
2. chlorobenze to phenol
3. ethene to 1,2 ethanediol
4. phenol to salicylaldehyde
5. methyl bromide to acetic acid
6. tolune to benzaldeyde
7. acetic acid to ethylamine
8. bezene to acetophenone
9. ethanol to propanone
10. benzoyl chloride to benzaldehyde
11. acetaldehyde to crotonaldehyde
12. Benzoyl chloride to benzaldehyde.
13. Acetic acid to acetone.
14. Ethyl isocyanide to ethyl amine.
15. Aniline to N-phenyl ethenamide.
16. Propane to 1- bromopropane.
17. 2propanol to lodoform.
18. ethene to ethanol.
19. phenol to phenylethanoate.
20. Ehenol to 2 propanol.
21. Propene to 2- propanone.
22. Aniline to p-Chloro benzene.
23. 2-propanol to 2-propanone.
24. Proponoic acid to 1 propanol
25. Acetophenone to benzoic acid.
26. Aniline to para bromobenzene
27. 2-Butonol from ethanol
28. Benzene to o nitro chlrobenzene
29. Propane from 2 propanol
30. phenol from aniline
31. Benzaldehyde in to acetaphenone
32. Melonic acid in to acetic acid
33. Acetaldehyde in to 2 butenol
34. Glycerol from glyceides
35. 2,4,6 tribromo phenol from phenol
36. Ethanoic acid to propanoic acid
37. Acetic acid to diethyl ammine
38. Nitro benzene to phenol
39. Aniline to benzoic acid
40. Phenol to 2acetoxybenzoic acid
41. benzene in to P chloronitrobenzene
42. Propanoic acid to acetic acid
43. Propanoic anhydride from propanoic acid
44. Ethyl amine to acetic acid
45. Methyl cyanide to acetaldehyde
46. Benzadehyde to cyanobenzene
47. Nitrobenzene to nitrophenol
48. Acetaldehyde into lactic acid

COMPUTER SCIENCE: SQL

Some SQL queries for you to solve.....
Consider the table given below and write the commands:




1.TABLE : EMPEMPNO NUMBER(4), ENAME VARCHAR2(10),JOB VARCHAR2(9), MGR NUMBER(4), HIREDATE DATE,SAL NUMBER(7,2),COMM NUMBER(7,2),DEPTNO NUMBER(2)


(a) To display the name, hiredate of all the employee hired after employee Jan 10th 1980.
(b) To display the highest and lowest salary for each department.
(c) To display the name of the employees whose job is in Clerk, Salesman, President
(d) To display all the types of jobs available in EMP table without repeating any.
(e) To display the name and salary of all the employees in the alphabetical order of name.



2.TABLE : EMPEMPNO NUMBER(4), ENAME VARCHAR2(10),JOB VARCHAR2(9), MGR NUMBER(4), HIREDATE DATE,SAL NUMBER(7,2),COMM NUMBER(7,2),DEPTNO NUMBER(2)


To display the ename, deptno and salary of all employee who do not get commission.
To count the number of employees in each department.
To display the ename and hiredate of all the employees whose name start with A.
To display the name, department number for all employees who work as Clerks and earns a salary more than 4000
To display the employee number and employee name in the descending order of salary.



3.TABLE : EMPEMPNO NUMBER(4), ENAME VARCHAR2(10),JOB VARCHAR2(9), MGR NUMBER(4), HIREDATE DATE,SAL NUMBER(7,2),COMM NUMBER(7,2),DEPTNO NUMBER(2)


(a) Display all the records (all columns) from table Emp.
(b) Display the difference of highest and lowest salary of each department
(c ) Display Ename, Sal and Sal added with Comm from table Emp.
(d) Display Ename with heading “Employee”, Sal*12 as “Total Salary” from table Emp.
(e) Display distinct Sal of employees from table Emp




4.TABLE : EMPEMPNO NUMBER(4), ENAME VARCHAR2(10),JOB VARCHAR2(9), MGR NUMBER(4), HIREDATE DATE,SAL NUMBER(7,2),COMM NUMBER(7,2),DEPTNO NUMBER(2)


1. Show the Structure of table EMP
2. Write a query to display EName and Sal of Employees whose salary isgreater than or equal to 3000 in ascending order of employee name.
3. Write a Query to display empno, employee name and department numberof all employees who have manager number between 7500 and 7900.
4. Write a Query to display name, job, salary, and HireDate of employeeswho are hired between February 20, 1981, and May 1, 1981. Order thequery in ascending order of HireDate.
5. Write a Query to display the name of employee whose name contains ‘T’as the last alphabet.

COMPUTER SCIENCE: PROGRAMMING IN C++

Here are a few C++ practical questions based on stacks, queues and binary files.
1.A queue containing telephone number is to be implemented using a linked list. Write a menu driven program using an object to insert a telephone number in the queue and to delete a telephone number from the queue


2.WAP using binary file create a book file for writing title, author, publisher and year. Display the file contents and perform search operation for a given title


3.A queue containing telephone number is to be implemented using a linked list. Write a menu driven program using an object to insert a telephone number in the queue and to delete a telephone number from the queue.


4.Write a program in C++ to create a binary file “House.dbf” with the following structure : Name, Class, Section and House and to do the following functions :
i) To append a record.
ii) To delete all class 12 records.
iii) To display all the records.


5.Consider a file ITEM.DAT with the following information:INo, IName, Qty, Rate, AmountInclude functions to perform the following:
a).Append records.
b) Modify the record in INo.
c).Display the record.


6.Consider a file EMP.DAT with the following information.Empname, Empno, salary, dept.Include the functions for the following operations
a).Append records.
b).Delete a record on empno.
c). Display all records.


7.A queue containing telephone number is to be implemented using an array. Write a menu driven program to insert a telephone number in the queue and to delete a telephone number from the queue.


{P.S. Pls. request if you need the solution for the above questions and specify the question no. }


8.Write a program in C++ to demonstrate PUSH, POP and display operations on a Array implementation of stack containing Roll no of students.

YOU HAVE COME TO THE RIGHT PLACE.....

The ultimate place to find notes, question papers, sample projects and everything you need to prepare for your CBSE board exam.

ALL THE BEST!!!