add up the total amount of fish there are all together at the initial date that would be 650 now add up 37 and 48 which is 85, now subtract that from 650 you will get 565 now multiply 5/7 by 650 to get 464 then subtract 464 from 565 to get 101 that's how many fish would need to be sold for there to be 5/7 of the store sold