In a computer game, a builder can build a wall in ten hours while a destroyer can demolish such a wall completely in fourteen hours. Both, the builder and the destroyer were initially set to work together on level ground. But after 7 hours the destroyer was taken out. What was the total time (in hrs) taken to build the wall ?
Most of the ozone in the atmosphere is found in the layer of stratosphere, which begins about 10.16 kilometers (6.10 miles) above Earth's surface and extends up to about 50 kilometers (31 miles) altitude.