Logical Reasoning - Logical Deduction - Discussion
In each question below are given two statements followed by two conclusions numbered I and II. You have to take the given two statements to be true even if they seem to be at variance from commonly known facts. Read the conclusion and then decide which of the given conclusions logically follows from the two given statements, disregarding commonly known facts.
- (A) If only conclusion I follows
- (B) If only conclusion II follows
- (C) If either I or II follows
- (D) If neither I nor II follows and
- (E) If both I and II follow.
Statements: All fishes are grey in colour. Some fishes are heavy.
- All heavy fishes are grey in colour.
- All light fishes are not grey in colour.
The premise nowhere says that all fishes are heavy.
If all fish are grey then how can a thing that isn't grey be a fish as they are all grey.
As conclusion 2 fails because there is nothing mentioned about light fishes.
And one fails because it is not mandatory that all heavy should be grey, if it was "some heavy are grey" then conclusion one would follow.