Temperature

[QQ2018789]

Question : The temperature of a city in November is -12°C . In December ,the temperature of the city decreases by a quarter of the temperature in November . What is the temperature of the city in December?
I thought we should take -12°C-((1/4)x(-12))
Which is equal to = -12°C+3°C
= -9°C.
But the Answer shows the Working like this :

-12+((1/4)x(-12)
=-12-3
=-15°C

Therefore , I don't understand that working.
What am I supposed to do with the Decreasing of anegative temperature?
Your help is much appreciated . Thank You

 

[mmm4444bot]

… the temperature of the city decreases …

-12°C + 3°C

By adding 3°, you increased the temperature. (-9 is larger than -12) :cool:

The answer needs to be smaller than -12° because we're told it's a decrease.

Subtracting positive amounts makes things smaller.

Subtracting negative amounts makes things larger.

So, we subtract a positive amount.

(-12° subtract 3°) is smaller than (-12°)


:idea: This exercise is a good lesson, for you. Be careful taking statements too literally; rely on foundations, to guide your thoughts.

When I first read the exercise, I pictured the Real number line, and I shifted -12 three units to the left because numbers decrease as we move to the left. In this image pulled from Google, we see that -5 is smaller than -1. If you start at -1, you can shift four units to the left to get -5.

-1 - 4 = -5

 

[QQ2018789]

Thank You

Thank You For helping me .?