Question

The temperature dropped 15 degrees in the last 30 days. If the rate of temperature drop remains the same how many degrees will the temperature drop in the next 10 days?

Answer 1

Hint: We will use here the very simple concept of ratio and proportion. First, we find the temperature drop in 1 day and then we multiply the temperature drop in 1 day by ten to get the temperature drop in the next 10 days.

Complete step by step solution: It is given that temperature drop in 30 days is $=15{}^\circ C$
 Therefore, temperature drop in 1 day \[={{\left( \dfrac{15}{30} \right)}^{{}^\circ }}C\]
 Now, using the simple unitary method:

Temperature drop in 10 days= (temperature drop in 1 day) $\times 10$
\[={{\left( \dfrac{15}{30} \right)}^{{}^\circ }}C\;\times {10}\]
$\Rightarrow{5}^\circ C$
Therefore, Temperature will drop by ${5}^\circ C$ in the next 10 days

Note: You must be very careful in the calculation part and don’t forget to write in the answer with proper units (here it is degree celsius).
A very important point in the question is that it is given that the rate of temperature drop is the same. If the rate of temperature drop was not the same, then we would not use this method to solve the problem. We may have to use integration methods to solve the problem.