There are 149 students in a parade square.
38 of the girls and
47 of the boys wear hats, there are 89 students in the parade square who do not wear hats. How many boys do not wear hats?
| |
Girls |
Boys |
Total |
| Do not wear hats |
5 u |
3 p |
89 |
| Wear hats |
3 u |
4 p |
60 |
| Total |
8 u |
7 p |
149 |
Number of students who wear hats
= 149 - 89
= 60
5 u + 3 p = 89 --- (1)
3 u + 4 p = 60 --- (2)
Make u the same.
(1)
x 3 15 u + 9 p = 267 --- (3)
(2)
x 5 15 u + 20 p = 300 --- (4)
(4) - (3)
(15 u + 20 p) - (15 u + 9 p) = 300 - 267
20 p - 9 p = 33
11 p = 33
1 p = 33 ÷ 11 = 3
Number of boys who do not wear hats
= 3 p
= 3 x 3
= 9
Answer(s): 9
