1, one (1)+ two (3), one (2)+ two (1), one (3)+ two (2)

2, 2 times (9 into the barrel, poured out at the end of 4, poured out at the end of 4, the remaining 1 into 4; 9 liters and a bucket, full of 4,

The remaining 6 liters are in a 9-liter bucket)

3. Slice ginger 1 min, wash the pan for 2 minutes, heat the pan for 2 minutes, heat the oil for 3 minutes (wash the fish for 3 minutes, cut the fish for 2 minutes), and fry for 7 minutes, which takes 15 minutes.

4. (20-4)/(14-10) =16/4 = 4 people.

5,24/0.8 = 30 km/h

165/30-0.8=5.5-0.8=4.7 hours

6. If there are more than X people, there are (100+x)/2 boys and (100-x)/2 girls.

60 *( 100+x)/2+70 *( 100-x)/2 = 63 * 100

5x=200 x=40

7.(300+240)/40= 13.5 minutes