MGMAT verbal guide

[nrohatgi]

When the temperature of a gas is increased, it is either accompanied by an increase in pressure if the gas is enclosed in a container, or an increase in volume if the gas is able to expand.

a) same
b) When the temperature of a gas is increased, it is accompanied either by an increase in pressure if it is enclosed in a container or
c) .....
d) Any increase in the temperature of a gas is either accompanied by an increase in pressure if it is enclosed in a container, or by
e) Any increase in the temperature of a gas is accompanied either by an increase in pressure if the gas is enclosed in a container or by

e is correct.

Now in this example:
Is it true that b) is wrong because it did not end in "by" ?
Why is d) wrong because of ","
Again my question is does it matter if the sequence is "accompanied either" Or "either accompanied"

[StaceyKoprince]

Yes, the sequence of the words matters. "Either X or Y" is an idiom. Whatever follows "either" (represented by X) must be parallel to whatever follows "or" (represented by Y).

So if I say "either accompanied by cheetos or..." I have to say "or accompanied by fritos." X = accompanied by cheetos, Y = accompanied by fritos
If I say "accompanied either by cheetos or..." now I just have to say "or by fritos." X = by cheetos, Y = by fritos

B does not repeat the second "by" and D does not repeat the "accompanied."