Help with some python homework...

Sun Feb 2 11:57:03 EST 2014

On Sunday, February 2, 2014 11:38:57 AM UTC-5, MRAB wrote:
> On 2014年02月02日 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ドル.95, but bookstores get a 40%
>> discount. Shipping costs 3ドル 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ドル 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ドル
>> >

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)