In 2007, Hunan college entrance examination asked the seventh question of liberal arts mathematics.
At 49 meters, it is 0.0 1, but the possibility considered here refers to the probability that it will appear when the water level is higher than this meter. So > =49 meters, which should be the total probability to the right of 49 meters, which should be 0.02; The total probability after 50 meters is 0.0 1. .