How much coffee of variety A, costing Tk. 5 a kg should be added to 20 kg of Type B coffee at Tk. 12 a kg so that the cost of the two coffee variety mixture be worth Tk. 7 a kg?

• ক 60 kg
• খ 70 kg
• গ 80 kg
• ঘ 50 kg ✅ সঠিক উত্তর