Question

A farmer bought 100 hens for Rs 4000, sells 20% of them at a gain
of 5%. At what gain percent must he sell the remaining so as to gain 20%​

Answer 1

Answer:

23.75%

Step-by-step explanation:

Total cost of hens = Rs 4000

Total no of hens = 100

cost of one hen = 4000/ 100 = Rs 40

In order to have total gain of 20%,

gain, 20% = 0.2 = (SP - CP)/ CP

or   0.2 = (SP - 4000) / 4000

or  SP = 800 + 4000 = Rs 4800

Now, 20% of hens (20 hens) are sold at a profit of 5%, i.e.

profit, 5% = (SP - CP)/ CP

     0.05 = (20*x - 20*40)/ (20*40) = (x - 40) / 40

or   2 = x - 40

or   x = Rs 42

SP of 20 hens = 20 *42 = 840

In order to have a total profit of 20%, he must sell remaining 80 hens for

4800 - 840 = Rs 3960

gain % for remaining 80 hens is

gain, y = (3960 - 80*40) / 80*40

          = (3960 - 3200) / 3200

         =  0.2375 or 23.75%