Walk away. Wait twenty minutes or so, to deflect suspicion. In those twenty minutes, get our unlimited supply of butane and put the container into our pocket.

You walk back out of the room and sit down to think about the conundrum of the message you found on the wall. You're supposed to prepare for combat, yet the manticore claims to be relatively calm. You can think of a variety of possible events, but the most probable ones are the manticore attacking you anyway, combat just after the manticore, or there being a combat encounter before that's no longer there. No matter what, you think you can expect combat very soon, so you get the butane from your backpack and put it in a pocket for easy access.

Come back. Answer the riddles with our answers.

He was walking.

"He was walking!"  you postulate. The manticore nods and gestures to the equation. Taking a piece of charcoal from hammerspace, you jot down some notes and swiftly solve the problem.

x^2-11x-42     a=1 b=-11 c=-42

Δ = b^2-4*a*c = (-11)^2 - 4*-42*1

                            = 121 + 168 = 289 > 0    --> √Δ is 17

                --> Equation has two different solutions.

x1 = (-b + √Δ)/2a = (11+17)/2 = 28/2 = 14

x2 = (-b - √Δ)/2a = (11-17)/2 = -6/2 = -3

Therefore, there are two solutions to the equation, x1 = 14 ; x2 = -3

"The two solutions are x=14 and x=-3!"  you propose. Again, the manticore nods. You think he looks somewhat impressed, but you're not quite sure. You move on to the last problem, with heavy use of charcoal and your mental notebook. It's pretty difficult.

[Long-ass explanation. Look in the comments section of the last chapter for the full deal.]

The answer is 7.764%.

Finally, you arrive at your answer, after half an hour of reinventing Bayesian equations.  "The answer to that last one is 7.764%"

The manticore grins at you (which is pretty difficult to tell, given that it's part lion and could very well be using some obscure feline facial expressions).  "Very good. You have solved all three problems and earned me quite a bit of money in the betting pool. I told those idiots I'd be the one to solve the problems first. Just sit around in a dungeon and you'll have adventurers stopping by to prove their worth every day."  It hands (paws?) you a bag with some unknown item inside and walks out.

Walk past the manticore, if he lets us, hand near the butane at all times.

You put your reward in your bag for now and move on, deeper into the dungeon, with a torch to guide your way. As you move through the corridor, you notice you're getting a bit... Woozy. You know, like the first time you had a cigarette. It's like nicotine shock, but also different - you figure it's whatever was coating the dart you got hit with earlier.

Entering the next room, something suddenly drops onto your back. Something huge. You fall to the ground and roll away from it. Getting a bit away, you stand up and look at it. It's a giant spider! Or arachnid, at least, it doesn't look like the spiders you're used to. Right now, you're really glad you don't have arachnophobia, that would seriously fuck up your day.

You absently pick up a cigarette you've rolled retroactively and light up. You can feel your badass points increasing (you know they say smoking isn't cool and all, but entering combat with one in your mouth is absolutely badass). Hopefully, the laws of reality will follow the Rule of Cool and give you a boost in battle. You quickly consider your options.

You're holding a spear and a torch. You have a decent amount of javelins. You have the energy blast spell. If you run away, you could see about putting a skill point into condensation to access the firebolt spell. If you fight, you could probably burn the spider. You recall reading a long time ago about insects using hair on their legs to sense their surroundings, if you burn them it might get disoriented. Of course, that was quite a while ago, so you could be remembering wrong.

What do you do?