In one Science class of 120 students, 0.1 of the boys and
34 of the girls passed the exam. A total of 64 students passed the exam. How many boys failed the Science exam?
|
Boys |
Girls |
Total |
Passed the test |
1 u |
3 p |
64 |
Failed the test |
9 u |
1 p |
56 |
Total |
10 u |
4 p |
120 |
0.1 of the boys =
110 of the boys
Total number of boys = 10 u
Total number of girls = 4 p
1 u + 3 p = 64 --- (1)
9 u + 1 p = 120 - 64
9 u + 1 p = 56 --- (2)
Make u the same.
(1)
x99 u + 27 p = 576 --- (3)
(3) - (2)
27 p - 1 p = 576 - 56
26 p = 520
1 p = 520 ÷ 26 = 20
From (2)
Number of boys who failed
= 56 - 1 p
= 56 - 20
= 36
Answer(s): 36