1. 66% of a 495 acre parcel of land is available for development. Of the developable portion, 31% is to be used for single family homes, while the remainder is to be used for multi-familiy townhomes. What percent of the parcel of land is used for single familyhomes?

2. 3.05 cubic metres of concrete contains 20.7% of water by volume. This exceeds the allowable water ratio, so the construction crew decides to try and salvage the mix by adding equal parts of aggregate and cement. If their new mix is 12.6% water, how many cubic metres of cement did they add?