What is the difference between an argumentative and a discursive essay?

Write an essay of 400 to 450 words on: "Cities are becoming unliveable. What should be done?"

Write an essay of 400 to 450 words on: "The book that changed the way I see the world."

Write an essay of 400 to 450 words on: "The place of failure in a young person's education."

Write a narrative essay of 400 to 450 words that ends with the sentence: "And that was the last time I ever saw the house on the hill."

Write an essay of 400 to 450 words on: "Artificial intelligence will change what it means to be educated."

How should a candidate plan an essay in the ten minutes before writing it?