Question 411200
b/j = 5/3, and
b - 15 = j + 15.
==> b = j + 30
Also, from the 1st equation, 3b = 5j.
==> 3(j + 30) = 5j
==> 3j + 90 = 5j
==> 90 = 2j
==> j = 45, the number of cards of Jim, and 
b = 45 + 30 = 75, the number of cards of Bob.