In a stall, some toy planes and mini-helicopters were on sale. ¹₄ of the items were toy planes. ²₃ of the toy planes and 208 mini-helicopters were sold. There were ¹₉ of the items left in the stall. How many toy planes and mini-helicopters were there in the stall at first?

	Toy planes	Mini-helicopters	Total
Comparing toy planes  and mini-helicopters at first	1x9 = 9 u	3x9 = 27 u	4x9 = 36 u
Before	3x3 =  9 u		9x4 = 36 u
Change	- 2x3 = - 6 u	- 208	- 8x4 = - 32 u
After	1x3 = 3 u	1 u	1x4 = 4 u

 
The total number of toys at first is repeated.  Make the total number of toys at first the same. LCM of 4 and 9 is 36.

The number of toy planes at first is repeated.  Make the number of toy planes the same. LCM of 9 and 3 is 9. 

Number of mini-helicopters left
= 4 u - 3 u
= 1 u

Number of mini-helicopters sold
= 27 u - 1 u
= 26 u

26 u = 208

1 u = 208 ÷ 26 = 8

Number of toy planes and mini-helicopters at first
= 36 u
= 36 x 8
= 288

Answer(s): 288