Selling university textbooks

Q: A common business practice amongst university students is to buy and sell their used textbooks amongst each other (as buying brand new textbooks from the publisher is extremely expensive).

1. Students, along with selling their textbooks, sell the notes that they made and the lecture slides (pdf version) for that module (subject) as part of one 'package'. Our question is regarding the permissibility of selling the lecture slides - which the lecturer uploads online during the course of the semester - as some naive first year students are unaware that they will be getting them for free over the course of the semester.

2. A lot of textbooks come in an ebook (pdf) format which the publisher sells online (also expensive). It is possible to find a 'pirated' copy of the ebook on the internet and download it. Students also sell these as well at a cheaper price.

2.1 Is this permissible?

2.2 If permissible (2.1), will one get thawaab if one distributes it to students for free instead of selling it to them?

Hadith regarding raisins being the cure for inferiority complex

Q: I read the following Hadith in a Tibb kitaab, however, the English translation of the last two words does not seem to be suitable. Please may the correct translation of the following be provided:

"Hazrat Ali (Radhiyallahu anhu) says that Rasoolullah (Sallallahu alayhi wasallam) said that those who take 21 raisins (الزبيب) daily will be free from all diseases which give rise to inferior complex. [Abu Nu-aim: 813]"

Reciting three Quls in the morning and evening

Q: What is the correct method of practising on this Hadith? Is it three times each?

Sayyiduna ‘Abdullah ibn Khubayb (radiyallahu’anhu) reports that Rasulullah (sallallahu’alayhi wasallam) said: ‘…Recite Qul huwallahu Ahad, Qul A’udhu bi Rabbil Falaq and Qul A’udhu bi Rabbin Nas, thrice every morning and evening. It will suffice you for everything.’

(Sunan Abi Dawud, Hadith: 5041 and Sunan Tirmidhi, Hadith: 3575) Imam Tirmidhi (rahimahullah) has declared this Hadith authentic (Hasan Sahih Gharib) . ‘Allamah Nawawi (rahimahullah) has also declared it authentic (sahih). Refer: Al-Adhkar, Hadith: 216.

Detergent leaking after placing the bottle in one's trolley

Q: Recently, while in a supermarket, I picked up a bottle of detergent and placed it in my trolley to purchase it.

A few minutes later, I saw that the bottle was leaking as the lid had not been screwed on completely. Approximately one quarter of the liquid had leaked out.

I left the bottle on the shelf, paid for my other items and left. It thereafter occurred to me that when I had picked up the detergent with the intention of purchase, I became liable for it. However, either the manufacturer or supermarket had not screwed the lid on correctly, and that was not my fault.

Am I responsible for the item? Should I return to the store and compensate them for it?