560/(1-20%-1/3) =1200 (volume)
2. The weight of a barrel of oil is 150kg. After 75% of the oil is sold, it will be sold at 10kg. At this time, the remaining barrels * * * weigh 35kg. How much should this oil drum weigh?
(150-10-35)/75% =140 (kg)-oil weight
150-140 =10 (kg)-barrel weight
The school bought a batch of new books and put them on two shelves, of which the number of books on the first shelf accounted for 58% of this batch of books. If you take 16 books from the first shelf and put them on the second shelf, then the books on the two shelves each account for 50% of this batch of books. How many books are there in this batch?
16/(58%-50%)=200 (Ben)
2. Two road teams, A and B, built a section of highway. Team A completed13 of this section in eight days, and then team B completed15 of the remaining works in four days. How many days does it take for two teams to work together?
1/3/8 = 1/24-A daily maintenance.
(1-1/3) *1/5/4 =1/30-shall be maintained by party b every day.
[1-1/3-(1-1/3) *1/5]/(1/24+1/30) = 7.