Library / /42 of 297

, 2014

Algebra Difficulty 1.2 Junior Find the answer Canada

At 2 p.m., Sanjay measures the temperature to be $3^\circ$ C. He measures the temperature every hour after this until 10 p.m. He plots the temperatures that he measures on the graph shown.

Hide/Reveal Data Table for Graph

Time of Day (p.m.)
Temperature (℃)

2
3

3
4

4
6

5
8

6
9

7
7

8
4

9
3

10
2

At what time after 2 p.m. does he again measure a temperature of $3^\circ$ C?

Pick one

Solutions — 2

Solution 1

The line representing a temperature of $3^\circ$ is the horizontal line passing halfway between $2^\circ$ and $4^\circ$ on the vertical axis.

There are two data points on this line: one at 2 p.m. and one at 9 p.m.

The required time is 9 p.m.

Solution 2

The line representing a temperature of $3^\circ$ is the horizontal line passing halfway between $2^\circ$ and $4^\circ$ on the vertical axis.

There are two data points on this line: one at 2 p.m. and one at 9 p.m.

The required time is 9 p.m.

Want a route through all this instead of an archive? The track puts 2,444 problems in a working order, from Junior Challenge level to the IMO shortlist.

Source: CEMC, University of Waterloo, licensed CC-BY-NC-4.0. Statement reproduced verbatim; metadata (topic, difficulty) added by this project.