Jan was a window cleaner. One morning, Jan was in a lift of a high building with his window cleaning tools when the building was on fire. There were five other passengers in the lift. All of a sudden the lift stopped. Although they didn't know what had happened outside, they had only 100 minutes to get out of the building before it would fall into the dust. Soon smoke began coming into the lift. The men knew that something was wrong. They tried to open the door but found a wall in front of them. The wall had the number 15 on it and they knew they were on the 15th floor. But their lift usually didn't stop there, so there was no opening for them to escape. Jan decided they would have to make their own. Knowing that the wall was made of a material that could be cut through, Jan took out his window cleaning tools, and began knocking a hole through the wall. When he felt tired, others helped. Starting with one small hole, they cut through the three-inch-thick wall. Then they kicked hard at the wall. The wall cracked apart. They saw before them a tile   wall! Refusing to give up, they knocked a hole through the tile, then made the opening big enough to get through. Surprisingly, the fire-fighters were outside the hole, they took Jan and his partners to the nearest stairs and they ran down the stairs as quickly as possible. By 10:23, Jan and the others ran out of the building. Five minutes later, the building burned down. How much time did they use up before getting out of the building?
5 minutes. 50 minutes. 95 minutes. 100 minutes.