'fewer' or 'less'?

Choose the CORRECT sentence:
1. There are less opportunities to find work in the countryside these days.
2. There are fewer opportunities to find work in the countryside these days.
Choose the CORRECT sentence:
1. People seem to have fewer free time than before.
2. People seem to have less free time than before.
Choose the CORRECT sentence:
1. Fewer children spend time reading books than when I was young.
2. Less children spend time reading books than when I was young.