If there are 4 families in a country with per capita income of $ 15000. The income of 3 families is $ 10000, $ 20000, and $ 12000. What is the income of the 4th family? (Board Term-I, Set-WQ7FXWC, 2014)

Question: If there are 4 families in a country with per capita income of $ 15000. The income of 3 families is $ 10000, $ 20000, and $ 12000. What is the income of the 4th family? (Board Term-I, Set-WQ7FXWC, 2014)

Answer: $ 18000