In one Mathematics class of 95 pupils, 0.1 of the boys and
23 of the girls passed the exam. A total of 52 pupils passed the exam. How many boys failed the Mathematics exam?
| |
Boys |
Girls |
Total |
| Passed the test |
1 u |
2 p |
52 |
| Failed the test |
9 u |
1 p |
43 |
| Total |
10 u |
3 p |
95 |
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 = 52 --- (1)
9 u + 1 p = 95 - 52
9 u + 1 p = 43 --- (2)
Make u the same.
(1)
x99 u + 18 p = 468 --- (3)
(3) - (2)
18 p - 1 p = 468 - 43
17 p = 425
1 p = 425 ÷ 17 = 25
From (2)
Number of boys who failed
= 43 - 1 p
= 43 - 25
= 18
Answer(s): 18
