PSLE In a school, 30% of the members in Reading Club and 80% of the members in Computer Club are girls. Both clubs have the same number of boys. The Computer Club has 75 more girls than the Reading Club. How many girls are there altogether?
|
Reading Club |
Computer Club |
Types |
Girls |
Boys |
Girls |
Boys |
Comparing the girls and the boys in each club |
3x1 |
7x1 |
4x7 |
1x7 |
Comparing the boys in 2 clubs |
|
1 |
|
1 |
|
3 u |
7 u |
28 u |
7 u |
30% =
30100 =
310 Fraction of the members in Reading Club that are boys
= 1 -
310 =
710 80% =
80100 =
45 Fraction of the members in Computer club that are boys
= 1 -
45 =
15 The number of boys in both clubs is the same. Make the numerators the same. LCM of 7 and 1 is 7.
7x110x1 of the members in Reading Club =
1x75x7 of the members in Computer Club
710of the members in Reading Club =
735 of the members in Computer Club
Number of more girls in Computer Club than Reading Club
= 28 u - 3 u
= 25 u
25 u = 75
1 u = 75 ÷ 25 = 3
Total number of girls
= 3 u + 28 u
= 31 u
= 31 x 3
= 93
Answer(s): 93