In one Science class of 120 pupils, 0.125 of the girls and
34 of the boys passed the test. A total of 35 pupils passed the test. How many girls failed the Science test?
|
Girls |
Boys |
Total |
Passed the test |
1 u |
3 p |
35 |
Failed the test |
7 u |
1 p |
85 |
Total |
8 u |
4 p |
120 |
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 = 35 --- (1)
7 u + 1 p = 120 - 35
7 u + 1 p = 85 --- (2)
Make u the same.
(1)
x77 u + 21 p = 245 --- (3)
(3) - (2)
21 p - 1 p = 245 - 85
20 p = 160
1 p = 160 ÷ 20 = 8
From (2)
Number of girls who failed
= 85 - 1 p
= 85 - 8
= 77
Answer(s): 77