At a party,
25 of the people are adults. The remaining group of people is divided into girls and boys in the ratio of 2 : 7. Each girl is given 3 keychains and each boy is given 4 keychains. Each accompanying adult receives 7 keychains. Given that only 560 keychains are given away to boys and adults, how many less girls are there than boys?
Girls |
Boys |
Adults |
3x3 |
2x3 |
2x1 |
7x1 |
|
2 u |
7 u |
6 u |
The number of children is repeated. Make the number of children the same. LCM of 3 and 9 is 9.
|
Girls |
Boys |
Adults |
Number |
2 u |
7 u |
6 u |
Value |
3 |
4 |
7 |
Total value |
6 u |
28 u |
42 u |
Number of keychains given away to boys and adults
= 28 u + 42 u
= 70 u
1 u = 560 ÷ 70 = 8
Number of less girls than boys
= 7 u - 2 u
= 5 u
= 5 x 8
= 40
Answer(s): 40