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 3 : 2. The ratio of the number of boys to girls in Group B is 1 : 1. There are 2 times as many students in Group B as in Group A. There are 20 more boys in Group B than Group A. What is the total number of students?
Group A |
Group B |
5 u |
2x5 = 10 u |
Boys |
Girls |
Boys |
Girls |
3 u |
2 u |
1x5 = 5 u |
1x5 = 5 u
|
Total number of students in Group A
= 3 u + 2 u
= 5 u
Total number of students in Group B
= 2 x 5 u
= 10 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 10 and 2 is 10.
Number of more boys in Group B than Group A
= 5 u - 3 u
= 2 u
2 u = 20
1 u = 20 ÷ 2 = 10
Total number of students
= 3 u + 2 u + 5 u + 5 u
= 15 u
= 15 x 10
= 150
Answer(s): 150