there is 15.39g of gold for every 2.77g of chlorine. In the other compound there is 7.74g of gold for every 4.18g of chlorine. What is the ratio of masses of gold in the two compounds?

i believe you are right for all except the 3rd ( look at sqdancefan his answer is much better)

a is the answer to this question

explanation:

on passing the small ampere of electric current through the tube made of ar and hg of cfl generates uv rays which excites the fluorescent and thus emits the high radiation by consumption of just 5- 12 w in comparison to incandescent light which requires more power such as around 40 - 55 w to lighten.

moreover the life span of fluorescent or cfl is around 8000 h whereas the life span of incandescent is around 1200 h

hence, the building installed with incandescent lights bears more electricity bill.