2 practical questions 1. Aunt Zhang used 8 tons of water last month, and the water charge was 24 yuan. Granny Li used 10 tons of water. How much was Granny Li's water charge last month? 2. To lay square bricks on the floor of a house, it needs 2000 bricks with a side length of 5 decimeters. If it is changed into 4 decimeters, how many bricks do it need?

2 practical questions 1. Aunt Zhang used 8 tons of water last month, and the water charge was 24 yuan. Granny Li used 10 tons of water. How much was Granny Li's water charge last month? 2. To lay square bricks on the floor of a house, it needs 2000 bricks with a side length of 5 decimeters. If it is changed into 4 decimeters, how many bricks do it need?

1. Water charge of last month = 10 × (24 △ 8) = 30 yuan
2.5 × 5 × 200 △ 4 △ 4 = 312.5 pieces
It costs 313 yuan

Two urgent questions
Xiao Dong is 1.6 meters tall. Standing on the playground, his shadow length is 2.4 meters. This is the measured shadow length of flagpole is 18 meters
The Olympic special train starts from Beijing and arrives in Tianjin at the speed of 300 km / h in 0.5 hours. It takes 18 minutes to return. How many km / h does it take to return?

Xiao Dong is 1.6 meters tall. Standing on the playground, his shadow length is 2.4 meters. This is the measured shadow length of the flagpole is 18 meters. 18 × (1.6 △ 2.4) = 12 meters. The flagpole is 12 meters long. The Olympic special train starts from Beijing and arrives in Tianjin at the speed of 300 kilometers per hour in 0.5 hours. It takes 18 minutes to return for some reason