An article which is marked at ₹ 1200 is available at a discount of 20% and the rate of GST is 18%. The amount of SGST is :

M.P. = ₹ 1200

Discount = 20% = $\frac{20}{100} \times 1200$ = ₹ 240

Price after discount = ₹ 1200 - ₹ 240 = ₹ 960.

GST = 18%

SGST = $\frac{GST}{2} = \frac{18}{2}$ % = 9%

= $\frac{9}{100} \times 960$

= 9 × 9.6

= ₹ 86.40

Hence, Option 4 is the correct option.