X is 3 times as fast as Y and is able to complete the work in 40 days less than Y. Find the time in which they can complete the work together?
Options:
A) 15 days
B) 16 days
C) 17 days
D) 18 days
E) 19 days
If X can complete work in x days and y can complete work in 3x days.   Then 2x = 40   x= 20 days.   so X can complete work in 20 days and y can complete work in 60 days.   they can complete the work together in 1/(1/20 + 1/60) = 1/ (4/60)= 
<gadget id="calculator">1/ (4/60)</gadget>
<output>15</output>
15 days   15 daysNSWER:15 days
<result>A</result>
X is 3 times as fast as Y and is able to complete the work in 40 days less than Y. Find the time in which they can complete the work together?