What is the sum of 2 / 3 of a tree and 3 / 5 of a tree? 40% of a number is 20 less than 1 and 1 / 5 of a tree Build a road. 3 / 10 of the whole stadium was built on the first day, and 40% of the total length was built on the second day. There are still 30 kilometers left. How long is the jump road 2 times 60 + 2x = 36

What is the sum of 2 / 3 of a tree and 3 / 5 of a tree? 40% of a number is 20 less than 1 and 1 / 5 of a tree Build a road. 3 / 10 of the whole stadium was built on the first day, and 40% of the total length was built on the second day. There are still 30 kilometers left. How long is the jump road 2 times 60 + 2x = 36

1、 1/(2/3+3/5)=15/19
2. Let this number be X
(1 and 1 / 5-40%) x = 20
X=25
3、 30/(1-3/10-40%)=100
4、 0.2*60+2X=36
12+2X=36
2X=24
X=12