Logical Puzzles - General Questions

If it takes 5 machines 5 minutes to make 5 widgets, how long would 100 machines take to make 100 widgets?

A bat and a ball cost Rs. 110 in total. The bat costs Rs. 100 more than the ball. How much does the ball cost?

You have 8 identical-looking balls; one is heavier. With a simple balance, what is the minimum number of weighings needed to find it for certain?

A rope ladder hangs over a ship's side with its bottom rung touching the water. Rungs are 20 cm apart. If the tide rises by 60 cm, how many rungs are under water?

If yesterday was Sunday, what day will it be the day after tomorrow?