Suppose you had the choice of either raising the high-temperature reservoir a certain number of kelvins, or lowering the low-temperature reservoir the same number of kelvins. Which would you choose (assuming you wanted to increase the efficiency, of course)? After doing experimenting with some random numbers, I thought the answer to be: lower the low-temperature reservoir. For example, 1 - 100/300 = 66.7% 1 - 95/300 = 68.3% 1 - 100/305 = 67.2% both of the last two are greater than the first, but the second has the greatest efficiency. However, my book says to raise the high-temperature reservoir. Is my book wrong?