Gimball Grace Limited manufactures a single model of electric fan heater. Each heater sells for £21. Variable costs of manufacture are £7.50. Fixed costs of the business are estimated at £54 000 for...

Gimball Grace Limited manufactures a single model of electric fan heater. Each heater sells for £21. Variable costs of manufacture are £7.50. Fixed costs of the business are estimated at £54 000 for the 2013 financial year. The net profit of the business in 2012 was £36 500, and the directors hope to increase that by 10% in 2013. How many fan heaters will they have to sell to reach their target net profit (to the nearest whole unit)?

a) 6 974

b) 4 000

c) 6 704

d) 7 374.