In one Mathematics class of 100 students, 0.125 of the girls and
34 of the boys passed the test. A total of 60 students passed the test. How many girls failed the Mathematics test?
|
Girls |
Boys |
Total |
Passed the test |
1 u |
3 p |
60 |
Failed the test |
7 u |
1 p |
40 |
Total |
8 u |
4 p |
100 |
0.125 of the girls =
18 of the girls
Total number of girls = 8 u
Total number of boys = 4 p
1 u + 3 p = 60 --- (1)
7 u + 1 p = 100 - 60
7 u + 1 p = 40 --- (2)
Make u the same.
(1)
x77 u + 21 p = 420 --- (3)
(3) - (2)
21 p - 1 p = 420 - 40
20 p = 380
1 p = 380 ÷ 20 = 19
From (2)
Number of girls who failed
= 40 - 1 p
= 40 - 19
= 21
Answer(s): 21