Question Discussion & Solution

Inheritance

The capability of a class to derive properties from another class is called Inheritance

• The class that inherits properties from another class is called Subclass or Derived Class.
• The class whose properties are inherited by a subclass is called Base Class or Superclass.

Syntax for Inheritance

class derived_name : access_mode base_class

{

//body of derived class

};

Additional Information 

Polymorphism

Polymorphism is mainly divided into two types:

• Compile-time Polymorphism
• Runtime Polymorphism

Compile-time polymorphism

This is achieved by function overloading or operator overloading.

• Function Overloading - When there are multiple functions with the same name but different parameters then these functions are said to be overloaded
• Operator overloading - When there are multiple operations can be performed by using single operator is called operator overloading for example operator ‘+’ when placed between integer operands, adds them and when placed between string operands, concatenates them

Run Time Polymorphism

It is achieved by Function Overriding.

Conclusion

Feature of Reusability is followed by inheritance so the correct answer is the inheritance.

Concept:

Software maintenance:

Any changes done in the software during its execution such as error correction, optimization etc. is software maintenance. Its objective is to preserve the value of software over time.

Explanation:

Types of software maintenance are:

Perfective maintenance: when there are new requirements from user side, then at that time changes made in the software is known as perfective maintenance. It makes the software more enhanced, clean structured, better than previous.

Adaptive maintenance: Changes done in the software environment that includes any work initiated as consequence of moving the software to different hardware or software is known as adaptive maintenance.

Preventive maintenance: It prevent software from future problems.

Given,

Given Expression: 70S7P21R2Q15

According to question :

=70 ÷ 7 + 21 × 2 – 15

Using BODMAS rule,

=10 + 21 × 2 – 15

= 10 + 42 – 15

= 52 – 15

= 37

Hence, value of the given expression is ‘37’.

The logic followed is:

The second is the currency of the first.

Hence, the correct answer is "Korea : Won"

For alphabet: Increase by + 4

 D + 4 → H + 4 → L + 4 → P + 4 → T + 4 → X

For Number: Decrease number by - 4

23 – 4 → 19 – 4 → 15 – 4 → 11 – 4 → 7 – 4 → 3