Question

A survey was taken of children between the ages of 10 and 17 about how many siblings they have and whether they have a pet. The results of the survey are shown in the table. Which statement must be true?
A. Out of the 125 children who do not have a pet, 18 of them have 2 siblings.
B. Out of the 97 children who have 1 pet, 40 of them do not have any siblings.
C. Out of the 125 children who do not have any siblings, 34 of them have a pet.
D. Out of the 97 children who have 1 sibling, 40 of them do not have a pet.

Answer 1

D. Out of the 97 children who have 1 sibling, 40 of them do not have a pet

Answer 2

Let's fill the table:

1. 34+18=52;

2. 97-57=40;

3. 34+57+x+6=125,

x=125-97,

x=28;

4. 28+15=43;

5. 6+2=8;

6. 18+40+15+2=75.

Then the table is:

$\begin{array}{cccccc} & \text{0 Siblings} & \text{1 Siblings} & \text{2 Siblings} & \text{3 or more Siblings} & \text{Total} \\ \text{Has a pet} & 34 & 57 & 28 & 6 & 125 \\ \text{Does not have a pet} & 18 & 40 & 15 & 2 & 75 \\ \text{Total} & 52 & 97 & 43 & 8 & 200 \end{array}$

Let's see the options:

A. Out of the 125 children who do not have a pet, 18 of them have 2 siblings.

This option is false, because 125 children have a pet, not as in statement.

B. Out of the 97 children who have 1 pet, 40 of them do not have any siblings.

This option is false, because 97 children have 1 Sibling, not 1 pet.

C. Out of the 125 children who do not have any siblings, 34 of them have a pet.

This option is false, because 125 children have a pet, not do not have siblings.

D. Out of the 97 children who have 1 sibling, 40 of them do not have a pet.

This option is true, you can see from the table that among 97 children that have 1 Sibling, exactly 40 do not have a pet.

Answer: correct choice is D.