Bunuel
A photographer has visited exactly 42 countries, all of which have been in Africa, Europe, or Asia. If the photographer has been to 6 more countries in Europe than in Asia, and twice as many in Africa as in Europe, how many countries in Asia has the photographer visited?
A. 4
B. 6
C. 12
D. 18
E. 24
Given: A photographer has visited exactly 42 countries, all of which have been in Africa, Europe, or Asia.
Asked: If the photographer has been to 6 more countries in Europe than in Asia, and twice as many in Africa as in Europe, how many countries in Asia has the photographer visited?
Let the countries visited in Africa, Europe and Asia be F, E & A respectively
A photographer has visited exactly 42 countries, all of which have been in Africa, Europe, or Asia.
F + E + A = 42. (1)
The photographer has been to 6 more countries in Europe than in Asia
E = A + 6. (2)
The photographer has been to twice as many countries in Africa as in Europe
F = 2E. (3)
Putting values of F & E in terms of A in (1)
2(A+6) + (A+6) + A = 42
4A = 42 - 18 = 24
A = 6
IMO B