It is given that the annual income of one among Augusta, Boliv and Centy is the average of the annual incomes of the other two. So, their incomes can be (40, 45, 50) lakhs or (40, 50, 60) lakhs or (45, 60, 75) lakhs in any order. Also, the absolute difference Augusta's income and Elin's income is 15 lakhs. So, their incomes can be (45, 60) lakhs or (60, 75) lakhs. If Augusta's, Boliv,s and Centy's incomes are (45, 60, 75) lakhs in any order, we will have three cases:
In case I, if Augusta's income is 45 lakhs, Elin's income must be 60 lakhs but either Boliv's or Centy's income is 60 lakhs. Case I is not possible. In case II, if Augusta's income is 60 lakhs, Elin's income must be 75 lakhs or 45 lakhs but Boliv's and Centy's income are 75 lakhs and 45 lakhs. Case II is not possible. In case III, if Augusta's income is 75 lakhs, Elin's income must be 60 lakhs but either Boliv's or Centy's income is 60 lakhs. Case III is not possible. So, Augusta's, Boliv's and Centy's income must be either (40, 45, 50) lakhs or (40, 50, 60) lakhs. Augusta's income can either be 45 lakhs or 60 lakhs. We get the following cases:
Diaz does not have the highest income. So, case I is not valid. Elin is the youngest male and Boliv is the older female. It is also given that the older female has more income. So, Boliv's income cannot be 40 lakhs because it is the least income. Thus, Boliv's income is 50 lakhs and Centy's income is 40 lakhs.
Centy is older that Boliv and Elin. So, Centy cannot be a female. Also, Augusta cannot be a female as Augusta's income is more than Boliv's. So, Diaz must be female.
Also, Centy is older than Boliv and Elin and Centy is having the least income. So, he can not be the oldest. Also, Elin has the highest income. So, he must be younger than one of the females and older than the other. Since, Elin is younger than Boliv, he must be older than the other female, Diaz. Thus, Augusta must be the oldest. The arrangement in the decreasing order of age is :
From the arrangement we can see that in both the cases, only the position of Boliv is same.
Hence, 1 is the correct answer.