Read the given statements and conclusions carefully and decide which of the conclusions logically follows from the statements.
Statements:
1. All boards are black.
2. All blacks are white.
Conclusions:
1. No white is black.
2. All black are boards.
3. All white are black.
4. All boards are white.

Correct option is A

1. No white is black. (False, there is no negative relation is given between them)
2. All black are boards. (False, same the above reason)
3. All white are black. (False, We can say all black is white and cannot say this)
4. All boards are white. (True, all the area of boards  is inside of white)

Only 4 is true.