There are eight equidistant points on a circle. How many right-angled triangles can be drawn using these points as vertices and taking the diameter as one side of the triangle?

Statements:No town is a city.

All cities are islands.

Conclusions:I. No island is a town.  

II. All islands are cities.

Statement: All calculators are buttons.

           All buttons are ovals.

Conclusions: I. Some calculators are ovals.

Statements: No laptop is a notebook.

All notebooks are monitors.

No monitor is a mouse.

Conclusions: I. No mouse is a monitor.

Statements:

All plates are cups.

All cups are oranges.

Conclusions:

I. Some oranges are cups.

Statements:

No number is a symbol.

No symbol is a letter.

No letter is a draft.

Conclusions:

Statement:

I) No A is B

II) No B is C

III) Some D are C

IV) All D are E

Conclusion:

I) Some E are not D

II) Some A are C

III) No C is A

Statement:

Each tiger is a lion.

Only a few lion are dogs.

Some dogs are cats

Conclusion:

Statements:

Some year are day.

Each year is month.

Only day are week.

Conclusions:

I. Some month are week.

II. Some month are year.

III. No year is week

Statements: All watches are clocks.

Some wall clocks are calculators.

Conclusions: I. No watch is a calculator.