PSLE Pupils in a school are put into two groups for an excursion.
14 of the pupils are in Group A and the rest in Group B.
17 of the pupils in Group A are girls. In the school,
27 of the pupils are girls. What fraction of the pupils in Group B are boys?
Group A |
Group B |
Total |
1x7 |
3x7 |
4x7 |
|
|
7x4 |
7 u |
21 u |
28 u |
Girls |
Boys |
Girls |
Boys |
Girls |
Boys |
1 |
6 |
|
|
2x4 |
5x4 |
1 u |
6 u |
7 u |
14 u |
8 u |
20 u |
The total number of students is repeated.
Make the total number of students the same.
LCM of 4 and 7 is 28.
Number of girls in Group B
= 8 u - 1 u
= 7 u
Number of boys in Group B
= 21 u - 7 u
= 14 u
Fraction of the pupils in Group B that are boys
=
1421=
23Answer(s):
23