In a stall, some water guns and rubber balls were on sale. ¹₁₀ of the items were water guns. ²₃ of the water guns and 444 rubber balls were sold. There were ¹₉ of the items left in the stall. How many water guns and rubber balls were there in the stall at first?

	Water guns	Rubber balls	Total
Comparing water guns  and rubber balls at first	1x9 = 9 u	9x9 = 81 u	10x9 = 90 u
Before	3x3 =  9 u		9x10 = 90 u
Change	- 2x3 = - 6 u	- 444	- 8x10 = - 80 u
After	1x3 = 3 u	7 u	1x10 = 10 u

 
The total number of toys at first is repeated.  Make the total number of toys at first the same. LCM of 10 and 9 is 90.

The number of water guns at first is repeated.  Make the number of water guns the same. LCM of 9 and 3 is 9. 

Number of rubber balls left
= 10 u - 3 u
= 7 u

Number of rubber balls sold
= 81 u - 7 u
= 74 u

74 u = 444

1 u = 444 ÷ 74 = 6

Number of water guns and rubber balls at first
= 90 u
= 90 x 6
= 540

Answer(s): 540