Question 602152
Delia	8	hours				
She does	  1/ 8	job in 1	hour			
Daisy	5	hours				
she does	  1/ 5	of thejob in 1	hour			
					
Together they will do		  1/ 8	+	  1/ 5	in 1 hour  
Together they will do		 13/40	of the job in one	hour 

Delia works for 3 hours alone
so in 3 hours she does 3* 1/8 = 3/8 of the job.
Balance job = 1-3/8= 5/8 of the job 

Together they do 13/40 of the job in 1 hour
They will take x hours to do 5/8 of the job

They will take (5/8) / (13/40) hours

=5/8 * 40/13
=25/13 hours
=

daisy will have to work with delia 25/13 hours