1, solution: let the height of the cylindrical iron block be x, from the meaning of the question:

8*7*6+5*5*5=π.(20/2)? x

The solution is x= 1.47.

2. Solution: Suppose that person X is transferred from team A to team B..

2(50-x)+ 1=4 1+x

The solution is x=20.

3. From the meaning of the question: 0.8*( 1+30%)*x

4. solution: let A * * * do x days, which is derived from the meaning of the question.

x/4+(x- 1)/8= 1

The solution is x=3.

It takes x days to complete the solution, which is deduced from the meaning of the question.

2( 1/ 10+ 1/ 15)+ 1/ 15+( 1/ 12+ 1/ 15)x = 1

The solution is x=4.