1, a rectangular iron sheet can make 60 equal cylindrical barrel bottoms or 40 equal cylindrical barrel sides, and a barrel can be made by matching one barrel bottom and one barrel side. Now there are two identical iron sheets. How many barrels can you make?

2. Party A and Party B leave at the same time. After meeting in E, Party A will continue to walk to B, and Party B will rest for 14 minutes, and then continue to walk until A..A and B arrive at B and A respectively, and then turn back immediately. There is still a chance in E to know that A walks 60 meters per minute and B walks 80 meters per minute. How many meters is there between A and B? (Proportional solution is required)

3. Xu Guangqi, a mathematician in Ming Dynasty, died in 1/22 and was born in 1607. He finished the translation of the first six volumes of Element. 1629 presided over the compilation of the new calendar but died unfinished. 1634 was finally completed by Li Tianjing. 1607 how old is Xu Guangqi?

Xiaoming goes home for dinner at 6 o'clock every day. One day, his mother waited from 6 o'clock until the hour hand and the minute hand were at right angles for the second time. When did Xiaoming go home?

1。 1÷( 1/60+ 1/40)=242。 Suppose when we first met, A made 3X and B made 4X.

2。 3x: 4x = (4x * 2): (3x * 2+14/60 * 80) gives X=4 4*(3+4)=28. . . . . . Total length 3. Solution: If the Gregorian calendar year in which he was born is X, there is1629-X.