A very big building in which thousand monkeys are living is lighted by thousand lamps. Every lamp is connected to a unique on/off switch, which are numbered from 1 to 1000. At some moment, all lamps are switched off. But because it is becoming darker, the monkeys would like to switch on the lights. They will do this in the following way.

Monkey 1 presses all switches that are a multiple of 1.
Monkey 2 presses all switches that are a multiple of 2.
Monkey 3 presses all switches that are a multiple of 3.
Monkey 4 presses all switches that are a multiple of 4.
Etc., etc.

How many lamps are switched on after monkey 1000 pressed his switches? And which lamps are switched on?

A hiker walked for two days. On the second day the hiker walked 2 hours longer and at an average speed 1 mph faster than he walked on the first day. If during the two days he walked a total of 64 miles and spent a total of 18 hours walking, what was his average speed on the first day?

I lived in a city that held as much as it could,
So I moved to another that repaid what it should.
The third had very little, with not much to be found,
The fourth was very boring, with no change in the sound.
The fifth was a jungle; wild beasts roamed the in street,
The sixth was so foggy you could not see past your feet.
The seventh was on the move; I could barely keep the pace,
The eighth was so evil; a whole city in disgrace.
The ninth was off-center; the people were bizarre,
The tenth was quite truthful; where honesty is par.
The eleventh was so wise; the acumen hurt my brain,
So I settled in a twelfth, because it was so plain.