3. Xiaolan 1.5m, her shadow is 2.4m long, and a tree shadow is 4m long. How tall is this tree? 5. How many hours does it take for a satellite to orbit the earth once, 10.6 hours, 14 weeks? 3. Solution: Let the height of this tree be 4/2.4X 1.5=2.5 (m).

1.5:2.4=x:4

2.4x=6

x=2.5

4. Solution: Let it take X days to complete 6X 12/8=9 (hours).

6X 12=8x

x=72\8

x=9

5. Solution: Let it run in x hours 6/10.6x 14 = 24.673333 (hours)14.

6: 14= 10.6:x

6x= 148.4

x=24.6733333

6. Solution: Assuming that X tons of salt can be dried, Y tons of seawater is needed.

100:3=585000:x

x= 17550

100:3 = y； nine

y=300

7. Solution: Let x hours return to the starting point of 60X6.5/78=5 (hours).

60X6.5=78x

x=5