The average weekly number of toy helicopters produced by Factory S and T is 3315. The average weekly number of toy helicopters produced by Factory S and U is 6465. If Factory T produced ²₇ as many toy helicopters as Factory U each week, how many toy helicopters does Factory S produce weekly?
Total toy helicopters that Factory S and Factory T produced
= 3315 x 2
= 6630

Total toy helicopters that Factory S and Factory U produced
= 6465 x 2
= 12930

Number of toy helicopters produced by Factory T = 2 u
Number of toy helicopters produced by Factory U = 7 u

Factory S's toys + 2 u = 6630 --- (1)
Factory S's toys + 7 u = 12930 --- (2)

(2) - (1)
7 u - 2 u = 12930 - 6630
5 u = 6300
1 u = 6300 ÷ 5 = 1260

Number of toy helicopters produced by T
= 2 u
= 2 x 1260
= 2520

Number of toy helicopters produced by S
= 6630 - 2520
= 4110

Answer(s): 4110