CEMC Pascal, 2023

Algebra Difficulty 1.4 Junior Find the answer Canada

On February 1, it was 16.2℃ outside Jacinta’s
house at 3:00 p.m. On February 2, it was -3.6℃ outside Jacinta’s
house at 2:00 a.m. If the temperature changed at a constant rate between
these times, the rate at which the temperature decreased was

Pick one

Solution

The total decrease in temperature between these times is $16.2\text{℃} - (-3.6\text{℃}) = 19.8\text{℃}$ .

The length of time between 3:00 p.m. one day and 2:00 a.m. the next day
is 11 hours, since it is 1 hour shorter than the length of time between
3:00 p.m. and 3:00 a.m.

Since the temperature decreased at a constant rate over this period of
time, the rate of decrease in temperature was $\dfrac{19.8\text{℃}}{11\text{ h}} = 1.8\text{℃}/\text{h}$ .

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