{1} Uncle Wang drives from place A to place B, and the first two hours travel 100KM. At this rate, it takes three hours to get from A to B. How far is the difference between A and B? (Use proportional solution)

Suppose the distance is x kilometers.

x/3= 100/2

2x=300

x= 150

{2} It took Uncle Wang three hours to drive from A to B, driving 50 kilometers per hour, and driving 60 kilometers per hour when he came back. How long did it take him to come back? (Solve in proportion-)

It took x hours.

60x=50×3

60x= 150

x=2.5

On a map with a scale of 1: 2000000, the distance between the two cities is 5.5CM. On another map with a scale of 1: 5000000, what is the distance of this road?

5.5×2000000÷5000000

=5.5×2÷5

=2.2 cm

The school held a group gymnastics performance. If there are 25 people in each row, there should be 24 rows. If there are not 20 people, how many columns should there be?

{All proportional solutions, equations}

Arrange x columns

20x=25×24

20x=600