In one Science class of 120 pupils, 0.25 of the boys and
23 of the girls passed the test. A total of 55 pupils passed the test. How many boys failed the Science test?
| |
Boys |
Girls |
Total |
| Passed the test |
1 u |
2 p |
55 |
| Failed the test |
3 u |
1 p |
65 |
| Total |
4 u |
3 p |
120 |
0.25 of the boys =
14 of the boys
Total number of boys = 4 u
Total number of girls = 3 p
1 u + 2 p = 55 --- (1)
3 u + 1 p = 120 - 55
3 u + 1 p = 65 --- (2)
Make u the same.
(1)
x33 u + 6 p = 165 --- (3)
(3) - (2)
6 p - 1 p = 165 - 65
5 p = 100
1 p = 100 ÷ 5 = 20
From (2)
Number of boys who failed
= 65 - 1 p
= 65 - 20
= 45
Answer(s): 45
