At the bird park were some adults.
12 of the number of locals was equal to 2 times the number of tourists. When another 11 tourists entered and 22 locals left, the ratio of the number of locals to the number of tourists become 5 : 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)x5 = (4) |
| Before |
8 u |
4 u |
1 u |
5 u |
| Change |
- 44 |
- 22 |
+ 11 |
+ 55 |
| After |
10 p |
5 p |
2 p |
10 p |
12 of the locals = 2 times of the tourists
1x22x2 of the locals =
2x11x1 of the tourists
Make the numerators the same. LCM of 1 and 2 is 2.
24 of the locals =
21 of the tourists
Locals : Tourists = 4 : 1
Make p the same.
(3) = (4)
8 u - 44 = 5 u + 55
8 u - 5 u = 55 + 44
3 u = 99
1 u = 99 ÷ 3 = 33
Number of locals at the bird park at first
= 4 u
= 4 x 33
= 132
Answer(s): 132
