Question

If a shopkeeper gives 10% discount on the MRP of a toy, his gain is 20%. If he had given a discount of 20%, his percentage of gain woulld be?

Answer 1

The higher the discount the lesser will be his gain and vice versa.

if discount is 10% gain is 20%

if discount is 20% gain is X

X= 10*20/20
  =10%

Answer 2

If a shopkeeper gives 10% discount on the MRP of a toy, his gain is 20%. If he had given a discount of 20%, his percentage of gain woulld be?

solution:
           Let  Cost Price = 100
           let MRP = Y
 therefore according to question ,
               If Discount is 10% on MRP , then
                 Selling Price =Y - 10/100*Y
                                     = 100Y - 10Y/100
                                   = 90/100*Y
                                    = 0.9 Y
       Gain = SP - CP
       10 = 0.9 Y - 100 ...........(1)
       100= 0.9Y - 10
         100+10 = 0.9Y
           110 = 0.9Y
           Y = 110/0.9
           Y=122.22
If Discount = 20% on MRP , then
                     SP = Y - 20/100*Y
                           = Y - 0.2 Y
                           = 0.8 Y
                           = 0.8*122.22
                           = 97.77
By giving the discount of 20% , the seller will incur a loss given by
                      = 100 - 97.77
                     =  2.22

Hence Loss = 2.22%

Hope this helps YOU!!