In one Social Studies class of 96 pupils, 0.25 of the girls and
23 of the boys passed the exam. A total of 54 pupils passed the exam. How many girls failed the Social Studies exam?
| |
Girls |
Boys |
Total |
| Passed the test |
1 u |
2 p |
54 |
| Failed the test |
3 u |
1 p |
42 |
| Total |
4 u |
3 p |
96 |
0.25 of the girls =
14 of the girls
Total number of girls = 4 u
Total number of boys = 3 p
1 u + 2 p = 54 --- (1)
3 u + 1 p = 96 - 54
3 u + 1 p = 42 --- (2)
Make u the same.
(1)
x33 u + 6 p = 162 --- (3)
(3) - (2)
6 p - 1 p = 162 - 42
5 p = 120
1 p = 120 ÷ 5 = 24
From (2)
Number of girls who failed
= 42 - 1 p
= 42 - 24
= 18
Answer(s): 18
