Question 632288
Crew I		--------	1.4	miles per day			
Crew II		--------	1.1	miles per day			
							
they are paving	towards	each other					
so add up rate of work							
1.4	+	1.1	=	2.5	miles per day		
Distance =		21.25	miles				
time = d/r							
time=  		21.25	/	2.5			
Time =   		8.5	days