In one Mathematics class of 100 pupils, 0.1 of the boys and
34 of the girls passed the test. A total of 49 pupils passed the test. How many boys failed the Mathematics test?
|
Boys |
Girls |
Total |
Passed the test |
1 u |
3 p |
49 |
Failed the test |
9 u |
1 p |
51 |
Total |
10 u |
4 p |
100 |
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 = 49 --- (1)
9 u + 1 p = 100 - 49
9 u + 1 p = 51 --- (2)
Make u the same.
(1)
x99 u + 27 p = 441 --- (3)
(3) - (2)
27 p - 1 p = 441 - 51
26 p = 390
1 p = 390 ÷ 26 = 15
From (2)
Number of boys who failed
= 51 - 1 p
= 51 - 15
= 36
Answer(s): 36