hi,
It would be great if someone could explain the logic behind the answer for the below question:-
Sentence Correction

Though glass is the conventional way of providing cheap, stable, and durable protection for motorists, but it is heavy, difficult to mould and potentially dangerous.

a) conventional way of providing cheap, stable, and durable protection for motorists, but it is heavy, difficult to mould and potentially dangerous.
b) conventional way of providing cheap, stable, and durable protection for motorists, it is also heavy, difficult to mould and potentially dangerous.
c) conventional way of providing cheap, stable, and durable protection for motorists, it is also heavy difficult to mould and is potentially dangerous.
d) conventional way of providing cheap, stable, and durable protection to motorists, it is also heavy, difficult to mould and potentially dangerous.
e) conventional way of providing a cheap, stable, and durable protection for motorists, it is also heavier, difficult to mould and potentially dangerous.

I chose (d) but it wasnt the correct answer because as per the solution, protection to X wasnt correct. Can you please explain why?
This was the reasoning:-
Choice (A) is wrong as 'though' does not need 'but' to complete. Choice (C) is wrong as it uses a superfluous 'is' before potentially dangerous. Choice (D) is idiomatically wrong as it uses 'protection to motorists'. The correct usage is 'protection for motorists'. Choice (E) uses the comparative degree 'heavier' when no comparison is being made. Choice (B) is the best option.


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The other question was:-
Playing football gives more exercise to players than playing rugby. Playing baseball gives more exercise to the player than playing chess. It thus follows, that playing football gives players more exercise than playing chess.
The above argument cannot be corrected by adding which of the following premise?

a) Playing rugby gives more exercise than playing baseball.
b) Playing rugby gives more exercise than playing chess.
c) Playing football and playing baseball gives the same amount of exercise.
d) Playing rugby and baseball gives the same amount of exercise.
e) Playing baseball gives more exercise than playing football.
My answer was c). The Argument is A>X and B>Y. now if A=B then A>Y. but this was the reasoning:-
Some information is missing in the passage, to help one logically draw the given conclusion, Choices (A), (B), (C), and (D), when added to the given information, help us to draw the conclusion that playing football gives more exercise than playing chess. But choice (E) still leaves the possibility of a game of chess giving more exercise in comparison to playing football. This is therefore the correct option
Can you please explain?

Thanks,
VivRash