1. There is a 2400-meter-long highway with colored flags on both sides (both ends are inserted), and the distance between adjacent colored flags is 30 meters. How many colorful flags have been planted on this highway?

(2400 ÷ 30+ 1) × 2 = 162.

2. There is a big round flower bed with a circumference of 180m. One boxwood is planted every 18m, and two ginkgo trees are planted between every two boxwood. How many trees are planted around the flower bed? How many meters are there between every two trees?

Yang shuyou

180/ 18 = 10 tree

Ginkgo tree has

10× 2 = 20 trees

* * * Planting trees

10+20 = 30 trees

Every two adjacent trees are separated.

180 ÷ 30 = 6m