What's round the number to the nearest 1

Tim's phone service charges $26.39 plus an additional $0.21 for each text message sent per month. if tim's phone bill was $31.64, which equation could be used to find how many text messages, x, tim sent last month?

Jayne is studying urban planning and finds that her town is decreasing in population by 3% each year. the population of her town is changing by a constant rate. true or false?

What’s the range cuz i can’t find it?