At a certain restaurant, the ratio of the number of cooks to the number of waiters is 3 to 8. When 12 more waiters are hired, the ratio of the number of cooks to the number of waiters changes to 1 to 4. How many cooks does the restaurant have?  Choose one:
A) 4 B) 6 C) 9 D) 12 E) 15
Originally there were 3k cooks and 8k waiters.   The new ratio is 1:4 which equals 3:12.   12k = 8k+12   k=3   There are 9 cooks.   The answer is 9.
<result>C</result>
At a certain restaurant, the ratio of the number of cooks to the number of waiters is 3 to 8. When 12 more waiters are hired, the ratio of the number of cooks to the number of waiters changes to 1 to 4. How many cooks does the restaurant have?