Question 77382
X*2X/(X+2X)
2X^2/3X
2X/3 USING 5 FOR X WE GET
2*5/3
10/3=3.33333 DAYS TO DO THE ENTIRE JOB.
THEREFORE THE WORK DONE AFTER 1 DAY IS 
1/3.33333=.3 OR 30% OF THE JOB CAN BE DONE IN 1 DAY.