Book object constructor with reading time calculation.

Using the tools from previous lessons, specifically the object constructor and method I wrote this short piece to provide information on a specified book and calculate reading time based on the user's wpm.

function Book(title, author, description, price, isbn, count) {
    this.title = title;
    this.author = author;
    this.description = description;
    this.price = price;
    this.isbn = isbn;
    this.type = "Book";
    this.count = count;
    this.readTime = function(wpm) {
        return this.title + " contains " + this.count + " words and, at " + wpm + " words per minute, will take you " + Math.floor(this.count / wpm /60) + " hours and " + Math.floor((this.count / wpm) - (Math.floor(this.count / wpm /60) * 60)) + " minutes to read.";
    };
} // Skip the semicolon this time (?)

var war_peace = new Book("War and Peace","Leo Tolstoy","In Russia's struggle with Napoleon, Tolstoy saw a tragedy that involved all mankind.",99,"0192833987",587287);
var cat_hat = new Book("The Cat in the Hat","Dr. Seuss","Poor Dick and Sally. It's cold and wet and they're stuck in the house with nothing to do.",7.5,"039480001X",1626);

var yourTime = war_peace.readTime(prompt("How many words per minute do you read?"));
console.log(war_peace.title + " is a " + war_peace.type + " by " + war_peace.author + ". You can buy it for $" + war_peace.price + ". " + yourTime);