The outside temperature at midnight today in Polina's hometown was 18 degrees Fahrenheit. The temperature increases by 1.2 degre
es Fahrenheit each hour over the next 15 hours. Polina's school does not send students outside for recess if the outside temperature is 32 degrees Fahrenheit or lower. Recess at her school always starts on the half hour or hour. Which statement is true about recess at Polina's school?
only students who have recess at 12 p.m. or later may go out
Step-by-step explanation:
Let the time after midnight be represented by t, and the temperature be y. Since the temperature increases by 1.2 degrees Fahrenheit each hour, the time taken to reach 32 degrees Fahrenheit can be gotten from:
y = 1.2t + 18
put y = 32
32 = 1.2t + 18
1.2t = 14
t = 14/1.2 = 11.67 hours
Since the recess starts at half hour or hour, hence the recess would start at t = 12 hours, i.e. at 12 p.m.
Hence only students who have recess at 12 p.m. or later may go out
