We must solve

Means the candles will be the same size in 4 hours
Answer:
a) 412 have a brother or sister in the school
b) 242 are girls
c) 339 are 13 years old or under
Step-by-step explanation:
Part a:
515 x 80%
412
Part b:
515 x 47%
242
Part c:
515 x 66%
339
I think what may be confusing is the fact that they also list two three digit numbers with two decimal places each. Since the number is greater than 4.49 with only two digits, it can't be 4.5 since the tenths place is odd. Same goes for less than 4.71. So the only answer would be 4.6--two digits, even tenths place, greater than 4.49 and less than 4.71.
Just some logical thinking, I guess. I think they were trying to trick you on this one.
Good luck.
Answer: x<-1
Step-by-step explanation: because anything less than -1 will give you more than 56