Answer :
Step-by-step explanation:
Selling price = Rs.80
Cost price = Rs.100
here, CP > SP
Now...
Loss ( L ) = CP - SP
= RS.100 - 80
= Rs.20
Now...
[tex]loss \: percent \: = \frac{loss}{CP} \times 100%[/tex]
[tex] = \frac{2000}{100} \\ [/tex]
= 20 %