The probability that store A does not earn a profit during the week is 0.6. If there are one or more purchases in the company, then the total income that can be obtained is normally distributed with a mean of 10000 and a standard deviation of 2000.

The probability that store B does not earn a week's revenue is 0.7. If there are one or more purchases in the store, then the total income that can be obtained is normally distributed with a mean of 9000 and a standard deviation of 2000

The total revenue of the two stores is independent of each other. Find the probability that too B's income is greater than that of store A's during the week.

The answer is 0.223 please explain why??