# Help with some python homework...

David Hutto dwightdhutto at gmail.com
Sun Feb 2 17:57:03 CET 2014

```On Sunday, February 2, 2014 11:38:57 AM UTC-5, MRAB wrote:
> 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
>
> >

Revised:

price_per_book = 24.95
percent_discount = .40
discounted_price = price_per_book - (price_per_book * percent_discount)
quantity = 60
shipping = 3.0 + ((quantity - 1)*.75)
total_price = (quantity * discounted_price) + shipping
print 'Total price: \$%d' % (total_price)

```