Solution: ∵ It takes 15 tons to burn 3 tons of coal every day.
Days used = 15÷3=5 (days)
In addition, the coal consumption was changed to half of the original, resulting in burning for 10 days.
∴ Coal consumption in later period =(3÷2)×(5+ 10)=22.5 (ton)
Coal storage capacity = 15+22.5=37.5 (ton)