Only Samarkand

Difficulty: Hard · Topics: Probability, Probability, Venn Diagrams

On a trip of 35 people, each person joined at least one of the Tashkent and Samarkand tours. The number who joined only the Tashkent tour is 10 less than 4 times the number who joined the Samarkand tour.

A person is chosen at random. Which of the following could be the probability that they joined only the Samarkand tour?