There are 6 cards (from 1 to 6 ) in a bowl. Now take out one
card from the bowl, then put it back, and then take out one
card for the second time. The number of the sum is 8.
Ask what is the probability that one of the card is 5?
【确认】2/5
N：please pay attention to the sentence that put it back
after the first time, that means it allows the repetition.
已知3^6x =8100, 求(3^(x-1))^3=?
【机委】10/3
In 1997, a company increased M percent of its cost of 1996,
and in the same year (1997), the same company increased N
percent of profit of 1996( where M>N ), ask the ratio of
cost to profit in 1997 increased by how many percent than the
