A fixed quantity of gas is taken through a sequence of pressure and volume changes. For two of the changes, neither the gas nor its surroundings do any work. For one change, the gas does work on the surroundings. For another change, the surroundings do work on the gas. What is the amount of work done on the gas during the change in which the surroundings do work on the gas?
- A$15\,\text{J}$
- B$25\,\text{J}$
- C$30\,\text{J}$
- D$45\,\text{J}$