For every 3 chocolates that Claire buys at the regular price, she buys a fourth chocolate for 25 cents. Claire buys 12 chocolates in total for $\$ 6.15$. What is the regular price of one chocolate, in cents?
(A) 180
(B) 45
(C) 60
(D) 54
(E) 57
For every 3 chocolates that Claire buys at the regular price, she buys a fourth for 25 cents. Consider dividing the 12 chocolates that Claire buys into 3 groups of 4 chocolates. In each group of 4, Claire buys 3 chocolates at the regular price and the fourth chocolate is
purchased for 25 cents.

That is, of the 12 chocolates that Claire buys, 3 are bought at 25 cents each while the remaining 9 are purchased at the regular price.

The total cost to purchase 3 chocolates at 25 cents each is $3 \times 25=75$ cents.

Since Claire spent $\$ 6.15$ and the total cost of the 25 cent chocolates was 75 cents, then the cost of the regular price chocolates was $\$ 6.15-\$ 0.75=\$ 5.40$.

Since 9 chocolates were purchased at the regular price for a total of $\$ 5.40$, then the regular price of one chocolate is $\frac{\$ 5.40}{9}=\$ 0.60$ or 60 cents.

ANSWER: $(\mathrm{C})$