Question 501649
woman----	10------0.10					
daughter-------	12-------0.08						
Together they do  0.18	of the job in one hour		
								
After 	1 hour						
Balance job 	0.82	

let second daughter take x hours to do 1 job
so she does 1/x of the job in 1 hour.	

All three do (1/x + 0.18 ) of the job in 1 hour
they have to complete 0.82 of the job so they will take 

0.82/(1/x+0.18) hours  ==> 3  	

0.82/(1/x+0.18)= 3
0.82= 3(1/x+0.18)
0.82/3 -0.18 = 1/x
1/x= 0.093
x= 10.75 hours.