Let CP = Rs. x SP = Rs. 240
Let profit be Rs. P.
Now, profit % = 20%
Since Profit % = (Profit/CP) x 100
20 = (P/x) x 100
P = 20x/100 = x/5
Profit = SP – CP = 240 – x
P = 240 – x
x /5 = 240 – x
240 = x + x/5
240 = 6×15
x = 1200/6
x = 200
So, CP = Rs. 200
New SP = Rs. 275 and CP = Rs. 200
Profit % = {(SP – CP)/CP} x 100
{(275 – 200)1200} x 100 = (75/200) x 100
= 7500/200
= 37.5%