Profit and Loss: if S.P and C.P are changed

Solving the problems if the S.P and C.P are changed.

Type1:

an article is sold at a profit of 10%. if both cost price and selling price are 50 less. the profit would be 5% more. find the cost price .


   if the cost price and selling price are reduced by same price,

                                             

                                                   = [(10 + 5)/5]*50
                                               
                                                   = 150

Type:2


if they are reduced are increased by different price.

An article is sold at 20% profit. if its C.P and S.P are less by 10 and 5 respectively the percentage profit increased by 10%. find the cost price?

     
Direct Formula: 

       increased% or decreased% of C.P = [100 + (20+10)]% * increased/decreased  C.P -increased or decreased S.P

     
the equation becomes,
if C.P = x
      10x/100 = (130/100) × 10 - 5

    x/10 = (13/10) × 10 - 5

x = (13 - 5) × 10  =   80

2. An article is sold at 25 % profit. if its C.P and S.P are increased by 20/- and 4/- respectively, the percentage of profit decreases by 15% find the cost price.

   Direct formula:

    15/100 of C.P = [110/100]20-4        [  note: 100+(25-15) = 110]

                    C.P         =  120