The average number of playing cards Jeremy and Brandon had was 426. The average number of playing cards Jeremy and Sam had was 225. If the ratio of Brandon's playing cards to Sam's playing cards was 5 : 2, find the number of playing cards Jeremy had.
Total number of cards that Jeremy and Brandon had
= 2 x 426
= 852

Total number of cards that Jeremy and Sam had
= 2 x 225
= 450

Number of playing cards Brandon had = 5 u
Number of playing cards Sam had = 2 u

Jeremy's cards + 5 u = 852 --- (1)
Jeremy's cards + 2 u = 450 --- (2)

(1) - (2)
5 u - 2 u = 852 - 450
3 u = 402
1 u = 402 ÷ 3 = 134

Number of playing cards that Sam had
= 2 u
= 2 x 134
= 268

Number of playing cards that Jeremy had
= 450 - 268
= 182

Answer(s): 182