1. Xiaoli, Xiaoming, Xiaoliang, Xiaofang's average height is 110cm. If Xiaodong's average height is 120cm, what's Xiaodong's height? 2. A and B planes fly out from two cities at the same time. After two hours, the planes meet at 120 kilometers from the midpoint. At this time, the ratio of the distance traveled by the planes is 3:2. What's the speed of the two planes? 3. The goods in the supermarket are sold out in three days. 50% of the total goods are sold in the first day. 210 more goods are sold in the third day than in the second day. The ratio of the number of goods sold in the second day to that in the third day is 5:8. How many goods are sold in these three days? Write to do so, write in plus 10 points

1. Xiaoli, Xiaoming, Xiaoliang, Xiaofang's average height is 110cm. If Xiaodong's average height is 120cm, what's Xiaodong's height? 2. A and B planes fly out from two cities at the same time. After two hours, the planes meet at 120 kilometers from the midpoint. At this time, the ratio of the distance traveled by the planes is 3:2. What's the speed of the two planes? 3. The goods in the supermarket are sold out in three days. 50% of the total goods are sold in the first day. 210 more goods are sold in the third day than in the second day. The ratio of the number of goods sold in the second day to that in the third day is 5:8. How many goods are sold in these three days? Write to do so, write in plus 10 points

Let Xiaodong's height be X
（110*3+X）/4=120
X = 150 cm