In one History class of 117 students, 0.1 of the boys and
23 of the girls passed the test. A total of 61 students passed the test. How many boys failed the History test?
| |
Boys |
Girls |
Total |
| Passed the test |
1 u |
2 p |
61 |
| Failed the test |
9 u |
1 p |
56 |
| Total |
10 u |
3 p |
117 |
0.1 of the boys =
110 of the boys
Total number of boys = 10 u
Total number of girls = 3 p
1 u + 2 p = 61 --- (1)
9 u + 1 p = 117 - 61
9 u + 1 p = 56 --- (2)
Make u the same.
(1)
x99 u + 18 p = 549 --- (3)
(3) - (2)
18 p - 1 p = 549 - 56
17 p = 493
1 p = 493 ÷ 17 = 29
From (2)
Number of boys who failed
= 56 - 1 p
= 56 - 29
= 27
Answer(s): 27
