Ask these three practical questions First, a batch of rice was delivered to the school canteen. In the first week, 15% of the total rice was eaten. In the second week, 320 kg rice was eaten, and 955 kg rice was left. How many kg of this batch of rice are there? Second, there is a batch of goods in the warehouse. One third of this batch of goods were transported away for the first time, and 9 tons were transported away for the second time, At this time, the ratio of the tonnage that has been transported to the tonnage that has not been transported is 7:5. How many tons are there in total? The third (the last): from station a to the station, the express trains can travel 84 kilometers per hour and arrive in 3 hours. It is known that the speed of ordinary buses is only 5 / 7 of that of express trains. How many hours can ordinary buses arrive

Ask these three practical questions First, a batch of rice was delivered to the school canteen. In the first week, 15% of the total rice was eaten. In the second week, 320 kg rice was eaten, and 955 kg rice was left. How many kg of this batch of rice are there? Second, there is a batch of goods in the warehouse. One third of this batch of goods were transported away for the first time, and 9 tons were transported away for the second time, At this time, the ratio of the tonnage that has been transported to the tonnage that has not been transported is 7:5. How many tons are there in total? The third (the last): from station a to the station, the express trains can travel 84 kilometers per hour and arrive in 3 hours. It is known that the speed of ordinary buses is only 5 / 7 of that of express trains. How many hours can ordinary buses arrive

1、（320+955）÷（1-15%）
=1275÷85%
=1500 (kg)
2、7+5=12
9÷（7/12-1/3)
=9÷1、4
=36 tons
3、（84×3）÷（84×5/7）
=252÷60
=4.2 (hours)

Ask some practical questions
1. A ball game should play 4 quarters, 12 minutes in each quarter, and 2 minutes between the upper and lower quarters. At least how long does it take to play such a ball game? (pause time is not included)
2. Hongshan village needs to build a road with a jump length of 1500 meters, which takes four out of five meters in 12 days. According to this calculation, how many days can it be completed?
3. The young pioneers planted 420 pine and cypress trees on the hillside. The cypress tree is one fourth of the pine tree. How many cypress trees are planted on the hillside?
(we need to make a formula and explain why we do it...)

Is it from grade 6? There are three breaks between the 1st and 4th stanzas (do you see if there are three gaps between your four fingers?), so: 12 * 4 + 2 * 3 = 54 (minutes) 2

A six kilometer road has been built for 3.6 kilometers. How many parts of the road are not built?
There are 120 boys in the grade, 20 less than girls. What percentage of the class are boys?
A is 75, 60 less than a, B and A. what's the percentage of a, B and a?
It's 1.2 times as much as already. B is 2.4 less than A. what's the percentage of a, B and a?

1.(6-3.6)/6=2/5
2.120/(120+120+20)=6/13
3.70/（75+60）=14/27
4. A = 14.4 B 12 A is a, 6 / 11 of B sum, B is a, 5 / 11 of B sum