In one Social Studies class of 116 pupils, 0.1 of the girls and
23 of the boys passed the test. A total of 49 pupils passed the test. How many girls failed the Social Studies test?
| |
Girls |
Boys |
Total |
| Passed the test |
1 u |
2 p |
49 |
| Failed the test |
9 u |
1 p |
67 |
| Total |
10 u |
3 p |
116 |
0.1 of the girls =
110 of the girls
Total number of girls = 10 u
Total number of boys = 3 p
1 u + 2 p = 49 --- (1)
9 u + 1 p = 116 - 49
9 u + 1 p = 67 --- (2)
Make u the same.
(1)
x99 u + 18 p = 441 --- (3)
(3) - (2)
18 p - 1 p = 441 - 67
17 p = 374
1 p = 374 ÷ 17 = 22
From (2)
Number of girls who failed
= 67 - 1 p
= 67 - 22
= 45
Answer(s): 45
