Question

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Class IX

Computer Project Questions (2020-21)


1.  Write a program to input any 50 numbers (including positive and negative).
    Perform the following tasks:
(a) Count the positive numbers
(b) Count the negative numbers
(c) Sum of positive numbers
(d) Sum of negative numbers


2.  Write a program to input marks in English, Maths and Science of 40 students who have    passed ICSE Examination 2014. Now, perform the following tasks:
(a) Number of students, who have secured 95% or more in all the subjects.
(b) Number of students, who have secured 90% or more in English, Maths and Science.

3. Write a program to input a number and display the new number after reversing the digits of the original number. The program also displays the absolute difference between the original number and the reversed number.
Sample Input: 194
Sample Output: 491
Absolute Difference= 297

4. The Greatest Common Divisor (GCD) of two integers is calculated by the continued division method. Divide the larger number by the smaller, the remainder then divides the previous divisor. The process repeats unless the remainder reaches to zero. The last divisor results in GCD.
Sample Input: 45, 20
Sample Output: GCD=5

5. Write a menu driven class to accept a number from the user and check whether it is a Palindrome or a Perfect number.
(a) Palindrome number: (A number is a Palindrome which when read in reverse order is same as in the right order)
Example: 11, 101, 151 etc.
(b) Perfect number: (A number is called Perfect if it is equal to the sum of its factors other than the number itself.)
Example: 6 = 1 + 2 + 3

6. Write a menu driven program to perform the following tasks by using Switch case statement:
(a) To print the series:
0, 3, 8, 15, 24, ............ to n terms. (value of 'n' is to be an input by the user)
(b) To find the sum of the series:
S = (1/2) + (3/4) + (5/6) + (7/8) + ........... + (19/20)

7. Using a switch statement, write a menu driven program to:
(a) Generate and display the first 10 terms of the Fibonacci series
0, 1, 1, 2, 3, 5
The first two Fibonacci numbers are 0 and 1, and each subsequent number is the sum of the previous two.
(b) Find the sum of the digits of an integer that is input.

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Sample Input: 15390
Sample Output: Sum of the digits = 18
For an incorrect choice, an appropriate error message should be displayed.

8.  Write a program to accept a number and check whether the number is divisible by 3 as well as   5 Otherwise, decide:
(a) Is the number divisible by 3 and not by 5?
(b) Is the number divisible by 5 and not by 3?
(c) Is the number neither divisible by 3 nor by 5?
The program displays the message accordingly.

9.

Write a program to input two unequal positive numbers and check whether they are perfect square numbers or not. If the user enters a negative number then the program displays the message 'Square root of a negative number can't be determined'.
Sample Input: 81, 100
Sample Output: They are perfect square numbers.
Sample Input: 225, 99
Sample Output: 225 is a perfect square number.
                         99 is not a perfect square number.

10

A cloth showroom has announced festival discounts and the gifts on the purchase of items, based on the total cost as given below:

Total Cost

Discount

Gift

Up to  Rs. 2,000

5%

Calculator

2,001 to  5,000

10%

School Bag

5,001 to  10,000

15%

Wall Clock

Above  10,000

20%

Wrist Watch

Write a program to input the total cost. Compute and display the amount to be paid by the customer along with the gift.

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Answer 1

Answer:

hLaw of Chemical Combination

(1) Law of Conservation of Mass

In a chemical change, total mass remains conserved. i.e. mass before the reaction is equal to mass after the reaction

H

2

(g)+Cl

2

(g)⟶2HCl

Mass before reaction=2+71=73g

Mass after reaction=2x36.5=73g

(2) Law of constant or Definite Proportions

All Chemical compounds are found to have constant composition irrespective of their method of preparation or source.

For g. in water (H

2

O)