Question

i bought a radio at ₹2200 and sold it with 20% profit what is its cp

Answer 1

Let the CP be Rs a 

Profit = 20 % of a

= 20a/100

= a/5

SP = a + a/5

=> 2200 = 6a/5

=> 6a = 2200 * 5

=> a = 5500/3

=> a = 1833.3

CP = Rs 1833  (approx..)

Answer 2

The cp is already is 2200 and the sp is = cp(100+gain%)/100
--> 2200(120)/100=2640