In one Social Studies class of 114 pupils, 0.25 of the boys and
23 of the girls passed the exam. A total of 46 pupils passed the exam. How many boys failed the Social Studies exam?
| |
Boys |
Girls |
Total |
| Passed the test |
1 u |
2 p |
46 |
| Failed the test |
3 u |
1 p |
68 |
| Total |
4 u |
3 p |
114 |
0.25 of the boys =
14 of the boys
Total number of boys = 4 u
Total number of girls = 3 p
1 u + 2 p = 46 --- (1)
3 u + 1 p = 114 - 46
3 u + 1 p = 68 --- (2)
Make u the same.
(1)
x33 u + 6 p = 138 --- (3)
(3) - (2)
6 p - 1 p = 138 - 68
5 p = 70
1 p = 70 ÷ 5 = 14
From (2)
Number of boys who failed
= 68 - 1 p
= 68 - 14
= 54
Answer(s): 54
