Question

A trader uses a tape of length 80 cm for 1 metre. he gives a discount of 20%. what is his profit or loss %

Answer 1

Let us assume price of 1 cm cloth is Re1 and he sells 80cm instead of 1 m.
Hence, CP of 80 cm cloth = Rs 80
SP of 80cm cloth = Rs 100(he will take money for 100cm from buyer)
Profit %(x) = $\frac{SP-CP}{CP}$× 100
              = $\frac{100-80}{80}$ × 100
              = $\frac{20 * 100}{80}$ = 25%
Seller gives discount of 20 % (y)
To find gain/loss, we will use successive gain/loss formula
= x-y +$\frac{x*(-y)}{100}$
= x-y -$\frac{xy}{100}$
= 25 -20 -$\frac{25*20}{100}$
= 25-20-5
= 0%
Hence, seller will neither have gain or loss.
Note: if answer is -ve , seller will have loss.
          if answer is +ve, seller will have gain.