851 - 170.20 (20% OFF) = ₹680.80

576.95 + 103.85 (18%) = 680.80

• 4 + @ 24% : 548.10 + 18% = 646.76
• 8 + @ 28% : 519.25 + 18% = 612.72
• 12 + @ 32% : 490.41 + 18% = 578.68