The average weekly number of robots produced by Factory H and J is 3320. The average weekly number of robots produced by Factory H and K is 6400. If Factory J produced ²₉ as many robots as Factory K each week, how many robots does Factory H produce weekly?
Total robots that Factory H and Factory J produced
= 3320 x 2
= 6640

Total robots that Factory H and Factory K produced
= 6400 x 2
= 12800

Number of robots produced by Factory J = 2 u
Number of robots produced by Factory K = 9 u

Factory H's toys + 2 u = 6640 --- (1)
Factory H's toys + 9 u = 12800 --- (2)

(2) - (1)
9 u - 2 u = 12800 - 6640
7 u = 6160
1 u = 6160 ÷ 7 = 880

Number of robots produced by J
= 2 u
= 2 x 880
= 1760

Number of robots produced by H
= 6640 - 1760
= 4880

Answer(s): 4880