PSLE In a school, 40% of the members in Singing Club and 80% of the members in Dancing Club are boys. Both clubs have the same number of girls. The Dancing Club has 20 more boys than the Singing Club. How many boys are there altogether?
|
Singing Club |
Dancing Club |
Types |
Boys |
Girls |
Boys |
Girls |
Comparing the boys and the girls in each club |
2x1 |
3x1 |
4x3 |
1x3 |
Comparing the girls in 2 clubs |
|
1 |
|
1 |
|
2 u |
3 u |
12 u |
3 u |
40% =
40100 =
25 Fraction of the members in Singing Club that are girls
= 1 -
25 =
35 80% =
80100 =
45 Fraction of the members in Dancing club that are girls
= 1 -
45 =
15 The number of girls in both clubs is the same. Make the numerators the same. LCM of 3 and 1 is 3.
3x15x1 of the members in Singing Club =
1x35x3 of the members in Dancing Club
35of the members in Singing Club =
315 of the members in Dancing Club
Number of more boys in Dancing Club than Singing Club
= 12 u - 2 u
= 10 u
10 u = 20
1 u = 20 ÷ 10 = 2
Total number of boys
= 2 u + 12 u
= 14 u
= 14 x 2
= 28
Answer(s): 28