862,840 is rounded to 900,000
61/4 % converted into a decimal is 15.25
Answer would be C.
Why A would be incorrect: 100m^2 is 100m × 100 m. That would be as big as a football field.
Why B would be incorrect: 1cm^2 is 1cm × 1cm. You can use a regular 15 cm to measure a piece of paper with the length of 1cm each side.
Why C would be correct: 1m^2 = 1m × 1m and it is also equals to 60cm × 60 cm. A 1 meter ruler = 60 cm = 4 times of your average 15 cm ruler. So, it is reasonable that a classroom is 10m by 10m in length and breadth.
Why D would be incorrect: The same explanation applies to here as well. Things that can be measured with 1m × 1m is a square table so your classroom can't be that small to fit an average of 30 to 40 students in there.
I hope my explanations were detailed and easy to understand. :)
