In one Chinese class of 112 students, 0.125 of the girls and
23 of the boys passed the mock exam. A total of 40 students passed the mock exam. How many girls failed the Chinese mock exam?
| |
Girls |
Boys |
Total |
| Passed the test |
1 u |
2 p |
40 |
| Failed the test |
7 u |
1 p |
72 |
| Total |
8 u |
3 p |
112 |
0.125 of the girls =
18 of the girls
Total number of girls = 8 u
Total number of boys = 3 p
1 u + 2 p = 40 --- (1)
7 u + 1 p = 112 - 40
7 u + 1 p = 72 --- (2)
Make u the same.
(1)
x77 u + 14 p = 280 --- (3)
(3) - (2)
14 p - 1 p = 280 - 72
13 p = 208
1 p = 208 ÷ 13 = 16
From (2)
Number of girls who failed
= 72 - 1 p
= 72 - 16
= 56
Answer(s): 56
