Accept every statement below as true, whatever the real world says. Which of the conclusions must then be true?
Statements:
1. Some cups are spoons.
2. Some plates are spoons.
Conclusions:
I. All plates may be cups.
II. Some spoons are plates.
Answer & explanation
Correct answer: option 4
The correct answer is Option (4) → Both conclusions I and II follow
A definite conclusion follows only if it is true in every diagram that fits the statements; a “may be” conclusion follows if it is true in at least one such diagram.
“Some cups are spoons”: the circles of cups and spoons overlap
“Some plates are spoons”: the circles of plates and spoons overlap; nothing is said about cups and plates
Conclusion I: All plates may be cups. — Follows. A “may be” conclusion follows if the statements allow it. The plate circle can be drawn inside the cup circle, still overlapping spoons, and both statements stay true.
Conclusion II: Some spoons are plates. — Follows. “Some plates are spoons” read the other way round is “some spoons are plates”.