PSLE The students at a sports meet are divided in Group A and Group B. The ratio of the number of boys to girls in Group A is 7 : 3. The ratio of the number of boys to girls in Group B is 14 : 1. There are 3 times as many students in Group B as in Group A. There are 273 more boys in Group B than Group A. What is the total number of girls?
Group A |
Group B |
10 u |
15x2 = 30 u |
Boys |
Girls |
Boys |
Girls |
7 u |
3 u |
14x2 = 28 u |
1x2 = 2 u
|
Total number of students in Group A
= 7 u + 3 u
= 10 u
Total number of students in Group B
= 3 x 10 u
= 30 u
The total number of students in Group B is repeated.
Use LCM to make the total number of students in Group B the same.
LCM of 30 and 15 is 30.
Number of more boys in Group B than Group A
= 28 u - 7 u
= 21 u
21 u = 273
1 u = 273 ÷ 21 = 13
Total number of girls
= 3 u + 2 u
= 5 u
= 5 x 13
= 65
Answer(s): 65