Answer:

15%

Step-by-step explanation:

840-714= 126

= 126 × 100

____

840

= 12600 = 15% discount

_____

840

[tex]Discount = \\ Marked \: price - Sales \: price [/tex]

[tex] = Rs \: 840 - Rs \: 714[/tex]

[tex] = Rs \: 126[/tex]

[tex]Discount = \frac{126}{840} \times 100[/tex]

[tex]Discount =15\%[/tex]