The average weekly number of toy helicopters produced by Factory X and Y is 3833. The average weekly number of toy helicopters produced by Factory X and Z is 6521. If Factory Y produced ²₅ as many toy helicopters as Factory Z each week, how many toy helicopters does Factory X produce weekly?
Total toy helicopters that Factory X and Factory Y produced
= 3833 x 2
= 7666

Total toy helicopters that Factory X and Factory Z produced
= 6521 x 2
= 13042

Number of toy helicopters produced by Factory Y = 2 u
Number of toy helicopters produced by Factory Z = 5 u

Factory X's toys + 2 u = 7666 --- (1)
Factory X's toys + 5 u = 13042 --- (2)

(2) - (1)
5 u - 2 u = 13042 - 7666
3 u = 5376
1 u = 5376 ÷ 3 = 1792

Number of toy helicopters produced by Y
= 2 u
= 2 x 1792
= 3584

Number of toy helicopters produced by X
= 7666 - 3584
= 4082

Answer(s): 4082