Help with some python homework...

[MRAB]

On 2014-02-02 16:11, David Hutto wrote:
> price_per_book = 24.95
> discount = .40
> quantity = 60
>
The original problem says:

Suppose the cover price of a book is $24.95, but bookstores get a 40%
discount. Shipping costs  $3 for the first copy and 75 cents for each
additional copy. What is the total wholesale cost for 60 copies?

> Here:
> discounted_price = (1-discount) * price_per_book
>
> The discounted price should be price_per_book - discount
>
No, the discount of 0.40 is 40%, not 40 cents.

> shipping = 3.0 + (60 - 1) * .75
> shipping should be, I think, should be 3.0 + (quantity  * .75)
>
No, the shipping is 75 cents starting from the second copy.

> total_price = 60 * discounted_price + shipping
> replace 60 with quantity (quantity * discounted_price) + shipping
>
> print total_price, 'Total price'
>
> total_price gives:
> 945.45 Total price
> and just 24.55(price per book - discount is ) * quantity is $1473 without the shipping, so the total is way off already:
>
>
> I think the following is what you're looking for:
>
> price_per_book = 24.95
> discount = .40
> quantity = 60
> discounted_price = price_per_book-discount
> shipping = 3.0 + (quantity*.75)
> total_price = (quantity * discounted_price) + shipping
> print 'Total price: $%d' % (total_price)
> Total price: $1521
>