Question

If by selling 10 bananas, the cost price of 8 bananas realized, then the gain percent is

Answer 1

The amount of bananas sold a re 10 bananas.

Let the cost price of each banana sold be x 

(Note: Cost price is the total amount of money that it costs a manufacturer to produce a given product)

cost price of 10 bananas = 10 × x= 10x
cost price of 8 bananas = 8 × x = 8x (this the amount or profit realized or gained as well)


Percent gain is calculated as follows:
 
% gain = profit/cost price × 100

            =  8x/10x × 100

            =  8/10 × 100

            = 0.8 × 100%

            = 80%

Therefore the % gain on selling the 10 bananas = 80%

            

Answer 2

Solution -

Let the cost price (CP) of one banana be Rs.1

Therefore, The (CP) of 8 bananas is Rs 8

Selling price (SP) of 10 banana = Cost Price of 8 bananas = Rs 8

SP of 1 banana = 8/10 =Rs 0.80

There is a loss... 

Loss = CP - SP
         = (1 - 0.80) = Rs 0.20

% loss = Loss/CP * 100 
           
           = (0.20/1) * 100

            = 20 %