(6,72:3/5+1 1/8·0,8):1,21-6 3/8;

Interpretation (using decimal comma as decimal point and colon as division):

(6,72 : 3/5 + 1 1/8 · 0,8) : 1,21 - 6 3/8

Steps:

• 6,72 ÷ (3/5) = 6.72 ÷ 0.6 = 11.2
• 1 1/8 × 0,8 = (9/8) × 0.8 = 0.9
• A = 11.2 + 0.9 = 12.1
• A ÷ 1,21 = 12.1 ÷ 1.21 = 10
• 6 3/8 = 6.375

Final result:

• 10 − 6 3/8 = 10 − 6.375 = 3.625 = 29/8 = 3 5/8

Answer: 3.625 (or 3 5/8, i.e., 29/8).