The average weekly number of robots produced by Factory J and K is 3401. The average weekly number of robots produced by Factory J and L is 6789. If Factory K produced ²₉ as many robots as Factory L each week, how many robots does Factory J produce weekly?
Total robots that Factory J and Factory K produced
= 3401 x 2
= 6802

Total robots that Factory J and Factory L produced
= 6789 x 2
= 13578

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

Factory J's toys + 2 u = 6802 --- (1)
Factory J's toys + 9 u = 13578 --- (2)

(2) - (1)
9 u - 2 u = 13578 - 6802
7 u = 6776
1 u = 6776 ÷ 7 = 968

Number of robots produced by K
= 2 u
= 2 x 968
= 1936

Number of robots produced by J
= 6802 - 1936
= 4866

Answer(s): 4866