case 1,
Let the CP be ₹x,
SP = ₹2400
Profit = SP – CP
= 2400 – x
Profit % = {(2400–x)/ x} × 100%
According to the question,
{(2400–x)/ x} × 100 = 25
=> (2400–x)/ x= 25 /100
=> 100(2400–x) = 25x [ cross multiplication]
=> 240000 – 100x = 25x
=> 240000 = 25x + 100x
=> 240000 = 125x
=> 240000/125 = x
=> x = 1920
So, CP = ₹1920
case 2,
SP = ₹2040
Profit = SP – CP
= 2040 – 1920
= ₹120
profit % = 120/1920 × 100%
= 16%