A and B complete a work in 4 days. A alone can do it in 6 days. If both together can do the work in how many days?
Choose the correct choice from the following answers:	A) 3.75 days	B) 3.7 days	C) 3.6 days	D) 2.4 days	E) 5.75 days

Rationale: "1 / 4 + 1 / 6 = 5 / 12 12 / 5 = 2.4 days answer : d"
Answer: D