The average number of playing cards Flynn and Archie had was 446. The average number of playing cards Flynn and Fabian had was 236. If the ratio of Archie's playing cards to Fabian's playing cards was 9 : 4, find the number of playing cards Flynn had.
Total number of cards that Flynn and Archie had
= 2 x 446
= 892

Total number of cards that Flynn and Fabian had
= 2 x 236
= 472

Number of playing cards Archie had = 9 u
Number of playing cards Fabian had = 4 u

Flynn's cards + 9 u = 892 --- (1)
Flynn's cards + 4 u = 472 --- (2)

(1) - (2)
9 u - 4 u = 892 - 472
5 u = 420
1 u = 420 ÷ 5 = 84

Number of playing cards that Fabian had
= 4 u
= 4 x 84
= 336

Number of playing cards that Flynn had
= 472 - 336
= 136

Answer(s): 136