What was the duration of calls (in minutes) from Zoya to Kabir?
Answer and solution
Correct answer: 50
Solution
Answer: 50
1. Kabir and Zoya are the only AeroNet users. The group is closed and self-calls are forbidden.
2. Kabir receives 50 minutes from AeroNet. Those calls can only originate from Zoya.
3. Therefore Zoya→Kabir=50 minutes. No individual outgoing=incoming assumption is needed.
Detailed setup and verification:
Follow the direction carefully: the question asks for calls made by Zoya and received by Kabir. In a two-person network with self-calls excluded, Kabir’s incoming AeroNet cell identifies that directed pair uniquely. Kabir’s outgoing 100 instead describes the opposite direction, Kabir→Zoya.
Verification: set Zoya→Kabir=50 and Kabir→Zoya=100. Kabir’s listed incoming 50 and outgoing 100 are both met. There is no reason for the two directions to have the same duration. The remaining cross-network and Vertex-only calls do not alter either number.
Verification: 3. Therefore Zoya→Kabir=50 minutes. No individual outgoing=incoming assumption is needed.
Trap to avoid: Do not reverse the caller and receiver.
1. Kabir and Zoya are the only AeroNet users. The group is closed and self-calls are forbidden.
2. Kabir receives 50 minutes from AeroNet. Those calls can only originate from Zoya.
3. Therefore Zoya→Kabir=50 minutes. No individual outgoing=incoming assumption is needed.
Detailed setup and verification:
Follow the direction carefully: the question asks for calls made by Zoya and received by Kabir. In a two-person network with self-calls excluded, Kabir’s incoming AeroNet cell identifies that directed pair uniquely. Kabir’s outgoing 100 instead describes the opposite direction, Kabir→Zoya.
Verification: set Zoya→Kabir=50 and Kabir→Zoya=100. Kabir’s listed incoming 50 and outgoing 100 are both met. There is no reason for the two directions to have the same duration. The remaining cross-network and Vertex-only calls do not alter either number.
G Strategy shortcut
Method: Two-person network: each incoming internal call must come from the other member.Verification: 3. Therefore Zoya→Kabir=50 minutes. No individual outgoing=incoming assumption is needed.
Trap to avoid: Do not reverse the caller and receiver.
G Strategy: Method: Two-person network: each incoming internal call must come from the other member. Verification: 3. Therefore Zoya→Kabir=50 minutes. No individual outgoing=incoming assumption is needed. Trap to avoid: Do not reverse the caller and receiver.