At the zoo were some adults.
12 of the number of locals was equal to 2 times the number of tourists. When another 23 tourists entered and 64 locals left, the ratio of the number of locals to the number of tourists become 7 : 5. Find the number of tourists at the zoo at first.
| |
Make p the same
(1)x5 = (3) |
Locals
(1) |
Tourists
(2) |
Make p the same
(2)x7 = (4) |
| Before |
20 u |
4 u |
1 u |
7 u |
| Change |
- 320 |
- 64 |
+ 23 |
+ 161 |
| After |
35 p |
7 p |
5 p |
35 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)
20 u - 320 = 7 u + 161
20 u - 7 u = 161 + 320
13 u = 481
1 u = 481 ÷ 13 = 37
Number of tourists at the zoo at first
= 1 u
= 37
Answer(s): 37
