The marginal propensity to withdraw (mpw\text{mpw}mpw) in an economy is 0.4. There is an injection of £160 billion£160\text{ billion}£160 billion into the economy.
What is the final increase in GDP?
£64 billion£64\text{ billion}£64 billion
£240 billion£240\text{ billion}£240 billion
£266.7 billion£266.7\text{ billion}£266.7 billion
£400 billion£400\text{ billion}£400 billion