At the concert hall were some adults.
12 of the number of locals was equal to 2 times the number of tourists. When another 31 tourists entered and 58 locals left, the ratio of the number of locals to the number of tourists become 5 : 3. Find the number of tourists at the concert hall at first.
| |
Make p the same
(1)x3 = (3) |
Locals
(1) |
Tourists
(2) |
Make p the same
(2)x5 = (4) |
| Before |
12 u |
4 u |
1 u |
5 u |
| Change |
- 174 |
- 58 |
+ 31 |
+ 155 |
| After |
15 p |
5 p |
3 p |
15 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)
12 u - 174 = 5 u + 155
12 u - 5 u = 155 + 174
7 u = 329
1 u = 329 ÷ 7 = 47
Number of tourists at the concert hall at first
= 1 u
= 47
Answer(s): 47
