In one Mathematics class of 113 pupils, 0.25 of the boys and
45 of the girls passed the exam. A total of 53 pupils passed the exam. How many boys failed the Mathematics exam?
| |
Boys |
Girls |
Total |
| Passed the test |
1 u |
4 p |
53 |
| Failed the test |
3 u |
1 p |
60 |
| Total |
4 u |
5 p |
113 |
0.25 of the boys =
14 of the boys
Total number of boys = 4 u
Total number of girls = 5 p
1 u + 4 p = 53 --- (1)
3 u + 1 p = 113 - 53
3 u + 1 p = 60 --- (2)
Make u the same.
(1)
x33 u + 12 p = 159 --- (3)
(3) - (2)
12 p - 1 p = 159 - 60
11 p = 99
1 p = 99 ÷ 11 = 9
From (2)
Number of boys who failed
= 60 - 1 p
= 60 - 9
= 51
Answer(s): 51
