Question

The temperature of certain places fell by \[{2^0}C\] ( a charge of \[{2^0}C\] ) each day for a week. What is the change of temperature over the whole week?

Answer 1

Hint: As we know that there are in total \[7\]days in a week and on each day the temperature of certain places fell by \[{2^0}C\]. So as we know that the temperature falls on one day is \[{2^0}C\]. And so the temperature fall for seven days can be calculated by applying a unitary method. And hence the required answer will be obtained.

Complete step-by-step answer:
As given that the temperature of certain places fell by \[{2^0}C\].
Hence, we know that in a week there are seven days.
So, the charge drop for one day is \[{2^0}C\].
So, it can be given as \[1day \to {2^0}C\]
The drop in temperature for seven days we have calculate as \[7day \to ?\]
Hence, applying unitary method on
\[
  1day \to {2^0}C \\
  7day \to ? \\
 \]
Let, the unknown temperature drop be x
So,
\[\therefore x = \dfrac{{2 \times 7}}{1}\]
On simplifying we get,
\[\therefore x = 2 \times 7 = {14^0}C\]
Hence, the temperature drop in seven days will be of \[{14^0}C\].

Note: The unitary method is a technique for solving a problem by first finding the value of a single unit, and then finding the necessary value by multiplying the single unit value. In essence, this method is used to find the value of a unit from the value of a multiple, and hence the value of a multiple.
Understand the question, form the equation and solve the calculation properly.