A certain store found that last year the average (arithmetic mean) monthly sales from January through October was $120,000. In November and December, the monthly sales were 3 and 5 times, respectively, the average for the other 10 months. What was the store's average monthly sales last year?
A) $180,000
B) $216,000
C) $252,000
D) $318,000
E) $360,000
A) $180,000
B) $216,000
C) $252,000
D) $318,000
E) $360,000
