pyq/2013/csat/60
In a rare coin collection, there is one gold coin for every three non-gold coins. 10 more gold coins are added to the collection, and the ratio of gold coins to non-gold coins becomes 1:2.
Based on this information, the total number of coins in the collection now becomes:
(A) 90
(B) 80
(C) 60
(D) 50