UPSC CSE Prelims 1997 Q146 — Science & Technology PYQ with Answer

Examine the following statements regarding a set of balls:

I. All balls are black.

II. All balls are white.

III. Only some balls are black.

IV. No balls are black.

Assuming that the balls can only be black or white, which two statements given above can both be true, but cannot both be false?

Choose the correct answer from the codes given below: