10 candles stand burning in a dining room. A strong breeze blows in through an open window and extinguishes 3 of them. Assuming the wind doesn't extinguish any more candles, how many candles do you have left in the end?
3. The 7 candles that manage to stay lit will melt down completely. The only candles that remain in the end are the 3 that are extinguished by the wind and therefore stay intact.
You have a 4 gallon and a 7 gallon jug of water. How can you measure exactly 6 gallons of water using these two jugs?