10. (15 points) 30 students are lined up in ascending order of height, with the height difference between any two adjacent students being the same. The sum of the heights of the first 10 students is 1450 cm, and the sum of the heights of the first 20 students is 3030 cm. What is the sum of the heights of all 30 students? $\qquad$ cm.
【Answer】Solution: Since the sum of the heights of the first 10 students is 1450 cm, and the sum of the heights of the first 20 students is 3030 cm,

the sum of the heights of the middle 10 students is: $3030-1450=1580$ (cm),
then the sum of the heights of all students is $1580 \times 3=4740$ (cm).
Answer: The sum of the heights of these 30 students is 4740 cm.
Therefore, the answer is: 4740.