Help with some python homework...

[David Hutto]

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)