A photographer has visited exactly 42 countries, all of which have been

[BTGModeratorVI]

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

Answer: B
Source: Kaplan

[Brent@GMATPrepNow]

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

Answer: B
Source: Kaplan

Let's solve the question using only one variable

The photographer has been to 6 more countries in Europe than in Asia
Let A = the number of countries visited in Asia
So, A + 6 = the number of countries visited in Europe

The photographer has been to and twice as many in Africa as in Europe
We already know that A + 6 = the number of countries visited in Europe
So, 2(A + 6) = the number of countries visited in Africa

The photographer has visited exactly 42 countries
We can write: A + (A + 6) + 2(A + 6) = 42
Expand and simplify the left side: 4A + 18 = 42
Subtract 18 from both sides: 4A = 24
Solve: A = 6

So, the photographer visited 6 countries in Asia

Answer: B

Cheers,
Brent