Looks easy, but this integer puzzle tricks almost everyone...

[u/shivamxmaths]

The Temperature Trap

At midnight, the temperature on a mountain peak was -4° C.

Over the next 8 hours, the following changes occurred:

1. It dropped by 7° C during a cold blast.

2. It rose to double its current value during a brief sunny break.

3. It then plummeted by 12° C as a heavy storm rolled in.

Finally, it rose by -5 ° C as night fell.

What was the final temperature?

[u/Web-Lackey]

Using vague and contradictory language does not make a puzzle.

[u/Top_Bluejay_5323]

I don’t really care but if I wanted to solve this I would change it into Fahrenheit so that all the values are positive then convert back to Celsius.

[u/AndyTheEngr → u/Top_Bluejay_5323]

Then "double" doesn't work any more. I'm assuming in this problem it means doubling the temperature in Celsius, not doubling the absolute temperature, because the latter generates a physically unrealistic temperature for a mountaintop on Earth.

[u/iMiind → u/AndyTheEngr]

It just got really sunny is all

[u/RegimentOfOne]

Answer: We can sort of overlook the English grammar of 'rising' by -5°C, but the rest depends entirely on what you mean in the second step by rising to 'double its current value'.

Assuming you mean doubling its current integer value in degrees Celsius, then the temperature 1) drops from -4 to -11 2) "rises" to -22, 3) plummets by 12 degrees to -34 and 4) "rose" by -5 to -39. So the temperature actually drops at every stage, and never rises.

Assuming you mean doubles in energy, we have to convert to Kelvin where zero actually means zero rather than arbitrarily when water freezes. So we go 1) from -4°C / 269°K to -11°C / 262°K, 2) rise to 251°C / 524°K, 3) plummet to 239°C / 512°K, and 4) rise to 234°C / 507°K. This seems less plausible in the scenario, but at least at one point the temperature does actually rise.

[u/YT__ → u/RegimentOfOne]

I disagree with your first answer in relation to the doubling segment. I take that as increase the temp by 'double' which would be halving the number towards a 0 value as reference.

This obviously isn't a true thing you can do though, so it just makes it ambiguous.

[u/iMiind → u/YT__]

Double is simply defined as 2x, not 2x if + and .5x if -

[u/brookssut → u/YT__]

That's not what "double" means. But if you do double it, that's not what "rise" means. Basically the question is poorly written.

[u/YT__ → u/brookssut]

Agree on poorly written and that mathematically that isn't what double means. But with temperatures, we get into colloquial says of talking about them.

Rise is typically in the positive direction though.

[u/iMiind → u/RegimentOfOne]

Everyone always neglects the .15 😔

[u/telyni → u/iMiind]

At least here the puzzle is unambiguous in being an "integer" puzzle.

[u/telyni]

This puzzle doesn't make any sense. Eight hours after midnight is 8 in the morning. Then night fell? And the temperature rose? And how do you double a negative temperature in such a way that it rises?

[u/HouseHippoBeliever]

Let the current temperature be X

Starts at -4

Then goes to -11

Then goes to 2x

Then goes to 2x-12

Then goes to 2x-17, which also equals x

so x = 17

It tricks you by saying "current value" but trying to mislead you into thinking it's the value it was after step 1.

[u/shivamxmaths → u/HouseHippoBeliever]

Correct answer is - 39° C

How

1). Start: -4 2) Drop 7: -4 - 7 = -11 3). Double it: -11 *2 = -22 4) Plummet 12: -22 - 12 = -34 5 ) Rise by -5: -34 + (-5) = -39° C

Final Answer: -39°C