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Preference share are those who fulfill two conditions:- 1.it has preferential right of dividend. 2.it has preferential right in regard to payment at the time of winding up of company.   And debentures are called acknowledgement of debt. 
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If you enroll for coaching with any institute .Following are the advantages:- 1. They teach you with different and shortcut method that make study easier. 2.you can aware of many things which you never heard. 3.they develop your personality . 4.they show you several ways to achieve your goal. 5.coaching centres are one who knows … Read more
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ABSTRACTION   :  Abstraction refers  to act of representing essential features without including the background details or explanations. Classes use the concept of abstracting and or defined as a list of abstract attributes such as size ,weight and cost and functions to operate on those attributes. ENCAPSULATION : Binding data and function into single class type variable called encapsulation.
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STANDARD DEVIATION  IS DEFINED AS THE SQUARE ROOT OF THE MEAN OF SQUARE OF DEVIATIONS FROM ARITHMETIC MEAN .IT IS REPRESENTED BY A SYMBOL  σ .  we calculate standard deviation by direct method and short cut method and step deviation method