In the past ten years, a country's total output has increased from 2000 to 3000, the capital stock has risen from 4000 to 5200, and the labour force has increased from 400 to 580. Suppose the elasticities aK = 0.4 and aN = 0.6. Show your work when you answer the following: a. How much did capital contribute to economic growth over the decade? b. How much did labour contribute to economic growth over the decade? c. How much did productivity contribute to economic growth over the decade?