A can do a job in 18 days and B can do it in 30 days. A and B working together will finish thrice the amount of work in ------- days?	Choose the correct choice from the following answers:
A) 21 ½ days	B) 22 ½ days	C) 33 3/4 days	D) 12 ½ days	E) None of these
Explanation:   1/18 + 1/30 = 8/90 = 4/45   45/4 = 45/4 *3 = 33 3/4 days   Answer: 33 3/4 days
<result>C</result>
A can do a job in 18 days and B can do it in 30 days. A and B working together will finish thrice the amount of work in ------- days?