But Mark Blaug, a noted historian of economic thought, points out that Marx wrote âno more than a dozen pages on the concept of social class, the theory of the state, and the materialist conception of historyâ while he wrote âliterally 10,000 pages on economics pure and simple.â 1
What do you do if you have flooded a lawnmower engine? (1) You can let it rest for about 20-30 minutes then try again. (2) You can remove the spark plug and crank the engine a few rounds to expel the extra fuel from the combustionâ¦ chamber.
Pipe A fills the tank in 20 minutes, so every minute it fills $\frac{1}{20}$ of the tank. Pipe B fills the tank in 30 minutes, so every minute it fills $\frac{1}{30}$ of the tank. Pipe C empties the tank in 40 minutes, so every minute it empties $\frac{1}{40}$ of the tank. The volume of the tank is equal to $\frac{1}{20}t+\frac{1}{30}t-\frac{1}{40}t$, with $t$ in minutes.