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 2 PSLE
John used a calculator to divide a 4-digit number by 1-digit number. For the 1-digit number, he made a mistake by pressing 4 instead of 5. He obtained the incorrect answer of 270. What should be the correct answer?