502 views

The question is based on the information provided below:

Eight fighter pilots flying over a conflict region notice some hostile activity taking place in a village. To peaceably resolve the conflict, they land their planes and decide that it would be best to send those pilots who would best complement each other as negotiators to talk to the warring parties. The pilots $\text{A, B, C, D, E, F, G,}$ and $\text{H}$ are chosen as negotiators according to the following conditions:

1. $\text{A}$ is chosen if $\text{B}$ is chosen.
2. If $\text{G}$ is not chosen, then $\text{A}$ and $\text{F}$ are chosen.
3. $\text{B}$ and $\text{H}$ are chosen if $\text{A}$ is chosen
4. If $\text{F}$ is not chosen, then $\text{G}$ is chosen
5. If $\text{H}$ is not chosen, then $\text{E}$ is chosen.
6. If $\text{C}$ is not chosen, then $\text{D}$ is not chosen, and if $\text{D}$ is not chosen , then $\text{C}$ is not chosen.

Which pair of pilots cannot be sent to negotiate if $\text{B}$ does not negotiate?

1. $\text{A}$ and $\text{H}$
2. $\text{G}$ and $\text{F}$
3. $\text{E}$ and $\text{H}$
4. $\text{G}$ and $\text{E}$

Option A. A and H

We can re-write the conditions as

$B \rightarrow A$

$G_{not} \rightarrow A, F$

$A \rightarrow B, H$

$F_{not} \rightarrow G$

$H_{not} \rightarrow E$

$C_{not} \rightarrow D_{not}$ & $D_{not} \rightarrow C_{not}$

From the condition 1 and 3 it clear that if B does not negotiate then  A and H can not be sent to negotiate.

by
3.3k points

### 1 comment

Your answer is correct, but can G and F or E and H be together?

Conditions 4 and 5 in your answer mean either/or, but not both and not none, right?