Question  Find  the selling price of  a  saree  after two successive discounts of 20 % .If the  price of that saree is
                 Rs800
Conventional  Method     800 x  20    =  160               800- 160 = 640 
                                          100

                                      640 x  20    =  128               640 -128 = 512
                                         100

                                     Total discount    is    800 -512      =   Rs288

                                      Effective Discount is                     =   288 x 100
                                                                                                 800
                                                                                         =    36 %

           You  can calculate it mentally .How ?

  Step1   Here first we calculate effective  discount  . Add  both discounts   Let it is  A
 
  Step2  Multiply  both discount and divide by 100  .Let it be B

 Step3    Subtract B from A    .That is our effective discount
           

                      ( 20 + 20 )  - (      20 x 20     )
                                                    100
                           40  -  4    =   36  %

                     Now find 36%of Rs 800     

                      =       320 - 32 =288     How?    For fast percentage  calculations see  Lesson no 19 &20

                             Selling price  800 - 288 = Rs 512

Question          If  a trader gives 20 %  retailer  margin and 3 % cash discount  , find the total effective discount?

                          20 + 3  -     20 x 3
                                              100

                             23    - .6     = 22. 4 %    

Home