An infinite number.
550
600
It is 600.
There are more than 5 numbers that can round down to 600 if rounding by hundreds. When rounding down by hundreds anything 601-649 rounds down to 600. If you're rounding by tens it would be anything 600-604.
0
There are 600 5-digit numbers divisible by 150.
Just 1 and 5.
600
70
600
There are infinitely many numbers, and their ranges will depend on the level to which the numbers are rounded.To the nearest 600: [300, 900)To the nearest 300: [450. 750)To the nearest 10: [595, 605)To the nearest 5: [597.5, 602.5) and so on.
600