Question

Staff employed in a UNESCO office in Paris are represented by four intersecting circles, one each for people who can read and write Russian, English, French and Spanish. The strength of people in some regions is given: \(a = 40, \quad c = 2a, \quad e = \frac{1}{2}a, \quad g = 2E\)

People who cannot read and write Russian, English and French are represented by

• A. l
• B. j
• C. h
• D. e

Hint:

If a person can't know Russian, English or French, only Spanish remains.

Answer 1

The Correct Option is D

Instead of hunting directly for the region, eliminate every option that still touches Russian, English or French.

1. Option A (l): this is the Russian-French-Spanish triple overlap, so a person here knows Russian. Ruled out.
2. Option B (j): this is the Russian-English-Spanish triple overlap, so a person here knows Russian and English. Ruled out.
3. Option C (h): this is the plain Russian-French overlap, so a person here knows Russian and French. Ruled out.
4. Option D (e): this is the "only Spanish" pocket, completely outside the Russian, English and French circles.

The only region left after eliminating everything that touches Russian, English or French is e, so option D is correct. \[ \boxed{e} \]