Question

A survey was conducted among 100 students of age groups 7-12 years and 13-18 years to find their favorite book genre. The students had to select any one genre out of detective, adventure, and biography. Out of the 50 students in the age group 7-12 years who participated in the survey, 23 liked adventure or biography. The total number of students of both age groups who liked detective books was 28. Using a two-way table, compute the total number of students in the age group 13-18 years who liked adventure or biography.
a. 23
b. 27
c. 49
d. 51

Answer 1

The correct answer is C. 49.

Remember that there are 100 students divided into 7-12 and 13-18 age group. So there should be 50 for each. The table should go like this:

7-12 age group
23 adventure or biography
27 - detective 

so you just have to subtract 50 from 23, which makes it 27. The remaining belongs to the 13-18 age group.

13-18 age group
1 - detective 
49 - adventure or biography.

Answer 2

Answer:

Option: C is the correct answer.

The number of students in the age group 13-18 years who liked adventure or biography are:

c.  49

Step-by-step explanation:

According to the given information in the table we can make a two-way frequency table as follows:

Age group          Adventure or Biography       Detective     Total

 7-12                              23                                    27               50  

 13-18                            49                                     1                  50

Total                             72                                    28               100

• As there are total 100 students and 50 students belong to the age group 7-12 years.

Hence, the remaining 50 students belong to the age group 13-18 years.

• Also, 23 liked adventure or biography in the age-group 7-12 years.

This means that the remaining out of 50 students like detective books.

Hence, number of students in age group 7-12 years who like detective is:

50-23=27

• Also, it is given that total 28 students like detective books.

 Hence, the number of students in the age group 13-18 years who like detective books is:

                        28-27=1.

• Also as there are total 50 students in age group 13-18 years out of which 1 student like detective books so the remaining will like adventure or biography.

Hence, the number of students who like adventure and biography in the age group 13-18 years is calculated as:

50-1=49 students.