There were 646 students in a school. On the school anniversary,
45 of the girls and
23 of the boys came in grey sweaters. The rest came in red sweaters. The number of boys who wore red sweaters was four times of the girls who wore red sweaters. How many students were in grey sweaters that day?
| Girls |
Boys |
Total |
| Grey sweaters |
Red sweaters |
Grey sweaters |
Red sweaters |
|
| 4 |
1 |
2x4 |
1x4 |
|
| |
1 |
|
4 |
|
| 4 u |
1 u |
8 u |
4 u |
17 u |
The number of boys who came in red sweaters is repeated. Make the number of boys who came in red sweaters the same. LCM of 1 and 4 is 4.
Total number of students
= 4 u + 1 u + 8 u + 4 u
= 17 u
17 u = 646
1 u = 646 ÷ 17 = 38
Number of students in grey sweaters
= 4 u + 8 u
= 12 u
= 12 x 38
= 456
Answer(s): 456
