A works 3 times as fast as B if B Completes work in 60 days, together they complete the same work?
Correct option is B. 15
Let the total work be $$W$$.Then, Speed of $$B = \dfrac{W}{60}$$ and Speed of A = $$\dfrac{3W}{60}$$
So, Time taken (in days) when they work together
$$= \dfrac{W}{\dfrac{W}{60}+\dfrac{3W}{60}}$$
$$= 15 \ days$$
Thus, correct answer is $$B.$$