Three medical experts, working together at the same constant rate, can write an anatomy textbook in 24 days. How many additional experts, working together at this same constant rate, are needed to write the textbook in 18 days?  Choose the correct answer.
A) 1	B) 2	C) 3	D) 4	E) 5
Each expert can write 1/72 of the book per day.   To complete the book in 18 days, we need 72/18= 
<gadget id="calculator">72/18</gadget>
<output>4</output>
4 experts, thus 1 more expert is needed.   The answer is 1.
<result>A</result>
Three medical experts, working together at the same constant rate, can write an anatomy textbook in 24 days. How many additional experts, working together at this same constant rate, are needed to write the textbook in 18 days?