Problem: Two colleagues studied human evolution, Dan studied early humans, from around 200,000 years ago, while Bob studied human settlements from 10,000 years ago. Which student learned less about nomadic gatherers?

A: Bob

Problem: David was conducting experiments on chemical equilibrium in the chemistry lab. First, he took a chemical system that was at equilibrium. He labeled it as case E. Then he changed the temperature of the system. He labeled that experiment as case T. Finally, he observed two more experiments, case A and case B. In case A forward reaction was favored, and in case B reverse reaction was favored. In which case the products concentration would decrease, case A or case B?

A: case B

Problem: Keith is an environmental scientist. He was studying the loss of ozone layer and its effect on different species. His data showed that in the beginning or twentieth century there were hardly any loss of ozone layer. He categorized that time period as time A. Further inquiry revealed that things didn't go well at the end of twentieth century - when there were severe loss of ozone layer. He categorized that time as time B. At what period would higher level of UV radiation reach earth, time A or time B?

A: time B

Problem: Two neighboring towns had different demographics. Hill town had younger inhabitants, most of them in their 30's and 40's. Lake town was inhabited by elderly people, most of them above 65 years of age. Which town had more people that have retired from work?

A:
Lake