Question

The number of girls who do wear a watch
is double the number who don't.
But the number of boys who do not wear a watch
is double the number who do.

If I tell you the number of girls in my class
is double the number of boys,
Can you tell me the number I teach? Here's a clue:
More than 20; below 32!

Answer 1

Answer:

Therefore total number of students is 27

Step-by-step explanation:

Let the number of girls who don't wear watch be x

Let the number of boys who wear watch be y

By data:

 Number of girls who wear watch=2x

 Number of boys who don't wear watch =2y

Total number of girls=3x

Total number of boys=3y

Total number of girls= double the number of boys

Therefore 3x=6y

          x=2y

The total number of students = 3x+3y

                                               =9y

Therefore the total number of students should be a multiple of 9

The only multiple of 9 between 20 and 32 is 27

Therefore total number of students is 27