//------------------------------//
// The Answer 15 
// Story: Life is a Test: A Series of Pony Logic Puzzles 
// by Brony_of_Brody 
//------------------------------//

Of course you shouldn't.

it sounds like a 90% success rate from the detector is reliable enough for all purposes, but you forget: the odds of a false reading (10%) is higher than you finding a rock that genuinely has inexplicablyvalumium (1%).

Imagine you searched 1000 rocks. A 1% pull-rate of inexplicablyvalumium means only 10 rocks are expected to have it. As for the other 990, with the detector giving off a false reading 10% of the time, 99 of them can be expected to set it off. That's a total of 109 rocks, and the one in Maud's cart at the moment could be any one of them.

With the odds of that rock having inexplicablyvalumium being 10/109, the odds are seriously stacked against you. There's no real sense in wasting 20,000 bits on what most of the time will be a worthless lump of rock.

Still, the fact Maud tried to pull a fast one on you...she must be a more shrewd businesspony than anypony realised.

"Heh. Didn't think I'd catch you with that. I see why Pinkie thinks so highly of you now."