Wilda can do the job in 4 hours ... she does 1/4 (or 0.25) of it each hour.
Karla can do it in 5 hours ... she does 1/5 (or 0.2) of it each hour.
Wilda worked alone for 1 hour ... 0.25 of the job was done before her helper 
arrived.  So only 0.75 of the job remained to be done together.
Working together, they accomplish (0.25 + 0.2) = 0.45 of the job in 1 hour.
How many times do they need to do  0.45  of the job in order to finish 
the  0.75  of it that remains ?  That's the number of hours it will take them, 
working together. 
0.75 / 0.45  =  <em>1 and 2/3</em>
After Wilda worked alone for 1 hour and Karla came along to join her, it will
take them another  <em>1 hour and 40 minutes</em> to finish the job and go for a swim.
        
             
        
        
        
Answer:
Step-by-step explanation:
        cost
d1     85
d2    110
d3    135
d4    160
 
        
             
        
        
        
Answer:
The answer to your question is the third option
Step-by-step explanation:
See the picture below
a) In the picture we observe that the parabola was narrowed not widened, so this option is incorrect.
b) From the picture, we conclude that the graph was shifted right 2 units, not four, so this option is incorrect.
c) From the picture, we observe that this option is the correct one.
d) We observe in the picture that this graph was not reflected so this option is incorrect.
 
        
                    
             
        
        
        
I can help! Do you have an example problem that I can show you step by step?