 Q10 - If "air" is equal to "1181", "muffin" is equal to...132266914
Each letter corresponds to a number, which number depends on its position in the alphabet. A is in position 1, B in position 2, C in position 3, and so on. M U F F I N corresponds to: 13 22 6 6 9 14
--By the solution's logic air should be 1918 which is clearly not 1181, which makes the questions impossible.

Q16 - Which one of these things is out of place?
Ball bearing, Tire and Rim are all spherical objects, while Piston rod is not.
---The solution is lying, ball bearings are indeed spherical but tires are tubular rings (for want of a better description) and rims are circles, neither of which are spherical.
My guess was tires are the only not metal component.

Q17 If I have 12 balls, and I lose half of them, then I retrieve 2/3 of them: how many balls do I have?
--This is a badly worded question. The second them could refer to the balls lost (intended), the balls you currently have (gives same answer), the original 12 balls (implies that one ends up with 8 balls)

Q22 - A contains one liter of water. You pour its content in B which contains 3/5 of A, then you pour the content of B in C which contains a half of A: how much water remains in B?
--This is a badly worded question. A contains one litre of water. You pour its content in(to) B which contains 3/5 of A. It could be that B is a large container already containing 3/5 of the content of A and so pouring A into B results in B holding 8/5 litres. Again C could be a large container containing half the original total of A, and so pouring B in results in C containing 21/10 litres and B none. Given the wording of the question this would be a valid interpretation.

Q27 - If ME + YOU + THEM = 4, then THEM - YOU - ME =