At the zoo were some adults.
12 of the number of tourists was equal to 2 times the number of locals. When another 18 locals entered and 12 tourists left, the ratio of the number of tourists to the number of locals become 8 : 3. Find the number of locals at the zoo at first.
| |
Make p the same
(1)x3 = (3) |
Tourists
(1) |
Locals
(2) |
Make p the same
(2)x8 = (4) |
| Before |
12 u |
4 u |
1 u |
8 u |
| Change |
- 36 |
- 12 |
+ 18 |
+ 144 |
| After |
24 p |
8 p |
3 p |
24 p |
12 of the tourists = 2 times of the locals
1x22x2 of the tourists =
2x11x1 of the locals
Make the numerators the same. LCM of 1 and 2 is 2.
24 of the tourists =
21 of the locals
Tourists : Locals = 4 : 1
Make p the same.
(3) = (4)
12 u - 36 = 8 u + 144
12 u - 8 u = 144 + 36
4 u = 180
1 u = 180 ÷ 4 = 45
Number of locals at the zoo at first
= 1 u
= 45
Answer(s): 45
