In one Chinese class of 120 pupils, 0.25 of the boys and
23 of the girls passed the mock test. A total of 40 pupils passed the mock test. How many boys failed the Chinese mock test?
|
Boys |
Girls |
Total |
Passed the test |
1 u |
2 p |
40 |
Failed the test |
3 u |
1 p |
80 |
Total |
4 u |
3 p |
120 |
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 = 40 --- (1)
3 u + 1 p = 120 - 40
3 u + 1 p = 80 --- (2)
Make u the same.
(1)
x33 u + 6 p = 120 --- (3)
(3) - (2)
6 p - 1 p = 120 - 80
5 p = 40
1 p = 40 ÷ 5 = 8
From (2)
Number of boys who failed
= 80 - 1 p
= 80 - 8
= 72
Answer(s): 72