A cellphone was marked at 40% above the cost price and a discount of 30% was given on its marked price.

Solution:

Let Rs 100 be the CP.

Then, marked price $=R s 140$

Discount $=30 \%$ of MP

$=\frac{30}{100} \times 140$

$=42$

Selling Price = marked price − discount

= 140 − 42

= Rs 98

Now, loss = CP − SP

= 100 − 98

= Rs 2

$\therefore$ Loss percentage $=\frac{\text { Loss } \times 100}{C P}$

$=\frac{2 \times 100}{100}$

$=2 \%$

Therefore, the shopkeeper had a loss of 2%.