A chemical plant used to use 12.5 tons of water per day. Due to improved water equipment, it can save 20 per day. How many days can the water consumption of the original 24 days be used now?

Method 1: Save 20 yuan of water every day, that is, the current daily water consumption is 12.5-12.5*20=10 tons

The original water consumption in 24 days was 12.5*24=300 tons

300 tons of water can be used for 300/10=30 days.

Method 2: 24/(1-20)=30 days