Math Question

Question

In Ms. Park's class, there are 16 students with glasses or brown hair (or both).  If 7 students have glasses and 14 students have brown hair, how many students have both glasses and brown hair?

Answer 1

16 have glasses, brown hair, or both.

7 have glasses which means 9 of the 16 do not have glasses.

14 have brown hair, which means 2 of the 16 do not have brown hair.

 

The most that could have brown hair and glasses is 7 since only 7 have glasses.

If the two who do not have brown hair wear glasses, then only 5 will have brown hair and glasses.

 

Thus, the answer is 5 to 7.

Answer 2

The total number of students who have glasses and/or brown hair is 16.

7 students have glasses and 14 students have brown hair.

7 + 14 = 21 so if there was no overlap between glasses and brown hair then there will be 21 students in all.

Subtract 16 from 21 to find out how many students have both glasses and brown hair.

So, students with glasses and brown hair = 21 - 16 = 5