A and B working alone can finish a task in 12 and 16 days respectively. In how many days can the task be finished if they work for one day each alternatively, and A begins the work?
12 \( \frac{1}{3} \)days
12 \( \frac{2}{3} \) days
13 \( \frac{1}{3} \) days
13 \( \frac{2}{3} \) days
(\(\sqrt{5}\) + \(\sqrt{7}\))² is a:
whole number
natural number
rational number
irrational number
In order to celebrate earth's environment and raise public awareness about pollution, which of the following days is observed worldwide as Earth Day each year?