Question: At the A-Street Fish Market a vendor sells fresh caught fish. His store is filled with 2/7 bass, 1/5 tuna, 1/7 trout, and the rest are catfish. If a customer just bought 1/7 of all the tuna and 1/7 of all the catfish, and a fisherman arrived to restock the bass, doubling the number of bass, what proportion of fish now in the store are trout?
Options:
(A) 30/71
(B) 4/7
(C) 5/43
(D) 1/2
(E) 1/5 Random thoughts:
Bass = 2/7 = 10/35
Tuna = 1/5 = 7/35
Trout = 1/7 = 5/35
Catfish = 1 - (10/35 +7/35 + 5/35) = 13/35
Purchased: Tuna = 7/35 - (7/35)(1/7) = 6/35, and
Catfish = 13/35 - (13/35)(1/7) = 12/35
Stocked: doubling the number of bass (2)(10/35) = 20/35
Now: 20 + 6 + 5 + 12 = 43
Trout proportion is now 5/43. The final answer: (C).