At the bird park were some adults.
12 of the number of locals was equal to 3 times the number of tourists. When another 11 tourists entered and 54 locals left, the ratio of the number of locals to the number of tourists become 7 : 2. Find the number of locals at the bird park at first.
|
Make p the same (1)x2 = (3) |
Locals (1) |
Tourists (2) |
Make p the same (2)x7 = (4) |
Before |
12 u |
6 u |
1 u |
7 u |
Change |
- 108 |
- 54 |
+ 11 |
+ 77 |
After |
14 p |
7 p |
2 p |
14 p |
12 of the locals = 3 times of the tourists
1x32x3 of the locals =
3x11x1 of the tourists
Make the numerators the same. LCM of 1 and 3 is 3.
36 of the locals =
31 of the tourists
Locals : Tourists = 6 : 1
Make p the same.
(3) = (4)
12 u - 108 = 7 u + 77
12 u - 7 u = 77 + 108
5 u = 185
1 u = 185 ÷ 5 = 37
Number of locals at the bird park at first
= 6 u
= 6 x 37
= 222
Answer(s): 222