# Required Packages
library(deSolve)
library(ggplot2)

solution <- ode(y=c(volume=100),
                times=seq(0, 10, by = 0.1), 
                func = function(time, state, parameters) {
                         volume = state[1]
                         d_volume = -0.1*time
                         return(list(d_volume))},) 

df <- as.data.frame(solution)

head(df)
# Plot the volume over time
plot <- ggplot(df, aes(x = time, y = volume)) +
  geom_line() +
  xlab("Time") +
  ylab("Volume") +
  ggtitle("Draining Water Tank") +
  theme_minimal()

# Save the plot as a PDF file
ggsave("draining_water_tank.pdf", plot, width = 8, height = 6)