Answer:
Balance as on 31st December = $46,000
Step-by-step explanation:
Sales October November December Balance
October $70,000 $14,000 $49,000 $7,000 $0
November $60,000 $12,000 $42,000 $6,000
December $50,000 $10,000 $40,000
Balance as on 31st December $46,000
Workings
October: 20% of 70,000 = 14,000, 70% of 70,000 = $49,000, 10% of 70,000 = $7,000
November = 20% of 60,000 = 12,000, 70% of 60,000 = $42,000, Balance = 60,000 - (12,000+42,000) = $6,000
December = 20% of 50,000 = $10,000, Balance = 50,000 - 10,000 = $40,000