At the tourist attraction were some adults. ¹₂ of the number of locals was equal to 3 times the number of tourists. When another 55 tourists entered and 47 locals left, the ratio of the number of locals to the number of tourists become 5 : 3. Find the number of locals at the tourist attraction at first.

	Make p the same (1)x3 = (3)	Locals (1)	Tourists (2)	Make p the same (2)x5 = (4)
Before	18 u	6 u	1 u	5 u
Change	- 141	- 47	+ 55	+ 275
After	15 p	5 p	3 p	15 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)
18 u - 141 = 5 u + 275
18 u - 5 u = 275 + 141
13 u = 416

1 u = 416 ÷ 13 = 32

Number of locals at the tourist attraction at first
= 6 u
= 6 x 32
= 192

Answer(s): 192