Question

Temperature at the foot of a mountain is \[ + {5^ \circ }{\text{C}}\] . It fell down by \[{10^ \circ }{\text{C}}\] at the top of the mountain. The temperature recorded on the top is
A. \[ + {15^ \circ }{\text{C}}\]
B. \[ - {15^ \circ }{\text{C}}\]
C. \[ + {5^ \circ }{\text{C}}\]
D. \[ - {5^ \circ }{\text{C}}\]

Answer 1

Hint: Here, in this question, temperature has fallen down at the top means we have to subtract \[{10^ \circ }{\text{C}}\] from the temperature at the foot of the mountain. So, the temperature at the top of the mountain is equal to temperature at the foot minus \[{10^ \circ }{\text{C}}\] .

Complete step-by-step answer:
Temperature can be both negative and positive. Positive temperature means hot and negative temperature means cold. Zero temperature is considered as a neutral point between positive and negative temperatures, the same as 0 on the number line between positive and negative integers. Celsius is the unit of temperature represented as \[^ \circ {\text{C}}\] .
Temperature at the foot of the mountain = \[ + {5^ \circ }{\text{C}}\]
Temperature at the top of the mountain is \[{10^ \circ }{\text{C}}\] less than temperature at the top of the mountain = \[ + {5^ \circ }{\text{C}} - {10^ \circ }{\text{C}} = - {5^ \circ }{\text{C}}\]
Thus, the temperature recorded on the top is \[ - {5^ \circ }{\text{C}}\] .
So, the correct answer is “Option D”.

Note: In these types of questions, as we know that temperature can be negative or positive, so careful about the subtraction of two temperatures. Understand the question and find what is asked in question, then do the calculations. Mostly we find the difference between the temperatures given in question and write the answer, which are not correct for every question. In this question, we can see that all options given are the results of either addition or difference of temperatures given in question. So, do not get confused with the options given, perform the steps properly and get the correct result. Also, temperature fell down means temperature get reduced and temperature raised means temperature increases