Level 2 PSLE
At first, the books in a library were placed on 30 shelves with an equal number of books on each shelf. 3 shelves were removed and the books on these shelves were placed on the remaining shelves. Because of this, the number of books on each remaining shelf increased by 5. What was the number of books on each shelf at first?
Level 3 PSLE
A shelf can be packed from end to end with 30 large books or 40 small books. Andy already packed the shelf with 5 large books and 25 small books. At most, how many more large books can Kevin pack the shelf with?