Question

The temperature of a certain place fell by ${2^ \circ }C$ (a charge of -${2^ \circ }C$) each day for a week. What is the change of temperature over the whole week?

Answer 1

Hint: We will multiply the change in temperature per day by the number of days in a week to get the change in temperature over the whole week.

Complete step-by-step answer:
We are given that the temperature of a place decreases per day by ${2^ \circ }C$ for a week.
We need to calculate the change of temperature over the whole week.
We know that there are a total 7 days in a week.
Now, the decrease in temperature on the first day will be${2^ \circ }C$. The second day, the decrease in the temperature will be ${2^ \circ }C$ less than the first day i.e., the total decrease in two days =$2 \times {2^ \circ }C = {4^ \circ }C$.
Here, we have already mentioned the decrease in the temperature. If we calculate the change in the temperature in these two days, it will be given as $ - {4^ \circ }C$.
Similarly, the decrease in the temperature over the week i.e., in 7 days, it will be = $7 \times {2^ \circ }C = {14^ \circ }C$
Hence, we can say that the change in the temperature over the whole week is $ - {14^ \circ }C$ .

Note: In this question, you need to understand the pattern of the temperature decrease per day over the week. You can also add up the individual change per day for a total of 7 days to calculate the total change over the whole week. We have placed a minus sign since it is decreasing in temperature i.e., deduction in the value of the temperature.