60/(1-1/4-1/3) =144 tons.
2. Two fifths of a steel pipe was used for the first time, 4.4m was used for the second time, and the remaining steel pipe was two fifths less than that for the first time. What is the original length of the steel pipe?
(4.4-2/5)/( 1-2/5-2/5) = 20m
3. Students in Grade 6 * * 180, among whom, one-ninth can swim and six-fifths can play the piano. How many people can play the piano?
180 * (1/9) * (6/5) = 24 people.
A highway is 45 kilometers long. Completed in the first month12km. How many kilometers will it take to complete four-fifths of this road in the second month?
45 * (4/5)-12 = 24km.
5. Our school donated books to poor areas, including 320 books in grade six, 6 books less in grade five than in grade four, and 30 books more in grade four than in grade six. How many books did you donate in the fifth grade?
320*(3/8)+30-6= 144 copies.
6. A barrel of oil, the first time poured out two fifths, the second time poured out 10 kg, and there was 10 kg left in the barrel. Q: How much does this barrel of oil weigh?
( 10+ 10)/( 1-2/5)= 100/3kg
7. An engineering team built a road. In the first month, it repaired two-fifths of the total length, in the second month, it repaired the remaining two-thirds, and in the third month, it repaired one-third of the total length less than in the first month, leaving 30 kilometers unfinished. How many kilometers is this road?
30/[ 1-2/5-( 1-2/5)(2/3)-(2/5- 1/3)]= 225km。