2. Pears with100kg have a water content of 90%. After storage for one week, the moisture content has dropped to 80%. How many kilograms is this batch of fruit now?
The circumference of rectangle is 88 cm. If the width increases by 25%, the length decreases by one seventh, and the circumference remains the same, how about the length of S =?
4. A two-story bookshelf with 40% books on it. If you put 48 books from the upper level to the lower level, the books from the lower level account for 75% of the total. How many books are there on this shelf?
5. Warehouse A has 120 tons of grain, and now 15% is transferred from warehouse A to warehouse B. At this time, warehouse A has 22 tons more than 80% of warehouse B. How many tons of grain does warehouse B have now?
6. The mid-term sports achievement rate of a school is 55%, and the final freshmen are 130, accounting for 80% of the total number. How many people are still not up to standard?