In a canteen,
13 of the students wore glasses. After 119 students who wore glasses entered the canteen, the percentage of students who wore glasses increased to 90%. How many students in the canteen did not wear glasses?
| |
Wore glasses |
Did not wear glasses |
| Before |
1x1 =
1 u |
2x1 =
2 u |
| Change |
+ 119 |
|
| After |
9x2 =
18 u |
1x2 =
2 u |
90% =
90100 =
910The number of students who did not wear glasses remains unchanged. LCM of 2 and 1 is 2.
Number of students who wore glasses and left
= 18 u - 1 u
= 17 u
17 u = 119
1 u = 119 ÷ 17 = 7
Number of students who did not wear glasses
= 2 u
= 2 x 7
= 14
Answer(s): 14
