Practice Exercise 1: Read the information provided and answer the questions which follow.
In one of the islands of Neverland, people from two tribes exist namely A and B. On the island there is no other tribe except these two. The activities of these tribes are governed by rigid norms and are strictly obeyed for marriages. The norms are:
> The people of one tribe cannot marry any other member of their own tribe though they can marry people from other tribe.
> After being married, each male member ceases to be a member of that tribe in which he was born and becomes the member of the tribe to which his wife belongs.
> The females continue to remain members of the tribe in which they are born even after marriage.
> On birth, the child becomes a member of the mother’s tribe.
> The male become members of the tribe in which they were born when they become divorcee or widower.
> As per norms, nobody can have more than one spouse at a given point of time.
1. A female in tribe B can have
I. Maternal Grandmother in tribe A
II. Paternal Grandmother born in tribe A
A. Only I can be true
B. Only II can be true
C. Both I and II are true
D. Neither I nor II can be true
2. A boy born in tribe B
A. Can have his daughter in tribe B
B. Can have his daughter-in-law in tribe A
C. Can have uncle from any tribe
D. Can have a divorced son in tribe B
3. Which of the following marriages are not permissible as per norms?
A. Any widower marries his wife’s sister
B. Any widow marries the former divorced husband of her daughter
C. Any girl of tribe B marries her mother’s brother
D. Any widower born in tribe A marries his brother’s widow
1. A female in tribe B would be born to a father from tribe A and a mother from tribe B. So, her paternal grandmother would belong to tribe A and her maternal grandmother would belong to tribe B. So, only II can be true. Therefore, B is the correct option.
2. Let’s check the options:
A. The boy after marriage would become a member of tribe A. So, her daughter would also be a member of tribe A. Therefore, this option is not correct.
B. After marriage, the boy would become a member of tribe A. So, his son would get married to a female in tribe B. Therefore, his daughter-in-law would be in tribe B. So, this option is also not correct.
C. Obviously, the boy can have an uncle from any tribe. So, this option is correct.
D. As discussed in option B, his son would get married to a female in tribe B. After divorce, his son would become the member of the tribe in which he was born, which is tribe A. So, this option is also not correct.
Therefore, C is the only correct option.
3. If the girl’s mother’s brother is unmarried, divorced or a widower, he belongs to the same tribe as that of girl. So, she won’t be allowed to marry him as marriages within the same tribe is not permitted.
If the girl’s mother’s brother is married, he would belong to the different tribe than that of girl. But since a person can have only one spouse at a time, she would still not be allowed to marry him.
Therefore, option C is correct.
Practice Exercise 2: In a family gathering there are two males who are grandfathers and four males who are fathers. In the same gathering, there are two females who are grandmothers and four females who are mothers. There is at least one grandson or a granddaughter present in this gathering. There are two husband-wife pairs in this group. These can either be a grandfather and a grandmother, or a father and a mother. The single grandfather (whose wife is not present) has two grandsons and a son present. The single grandmother (whose husband is not present) has two granddaughters and a daughter present. A grandfather or a grandmother present with their spouses does not have any grandson or granddaughter present. What is the minimum number of people present in this gathering?
In all, there are 3 generations present. We need to figure out the minimum number of people based on the constraints given.
> The single grandfather (whose wife is not present) has two grandsons and a son present.
> The single grandmother (whose husband is not present) has two granddaughters and a daughter present.
> A grandfather or a grandmother present with their spouses does not have any grandson or granddaughter present.
Based on these 3 clues, we can draw the family structure as shown:
Now let’s use other clues:
> There are two males who are grandfathers and four males who are fathers.
We have 2 males who are grandfathers. Including them and a father from 2nd generation, in all, we have 3 fathers. We need to introduce 1 more father.
> There are two females who are grandmothers and four females who are mothers.
We have 2 grandmothers and in all, 3 mothers. We need to introduce 1 more mother.
> There is at least one grandson or a granddaughter present in this gathering.
We have 2 grandsons and 2 granddaughters in our family structure. Therefore, this condition is fulfilled.
> There are two husband-wife pairs in this group.
We have 1 husband-wife pair. We need to introduce 1 more husband-wife pair.
So, we see we need to introduce 1 father, 1 mother and 1 husband-wife pair. A simple way to do it is to introduce a husband-wife pair in the 2nd generation.
Now we have 2 husband-wife pairs, 4 fathers, 4 mothers and no grandchild for the grandfather present with his spouse. This family structure fulfills all the conditions given.
Therefore, a minimum number of 12 people are present in this gathering. So, B is the correct option.