Answer: 12 hours
Step-by-step explanation:
Given : Working together, it takes Sam, Jenna, and Francisco two hours to paint one room.
When Sam works alone, he can paint one room in 6 hours. When Jenna works alone, she can paint one room in 4 hours.
Let 't' be the time taken by Francisco to paint one room on his own.
Then , we have
Rate of work of Sam +Rate of work of Jenna + Rate of work of Francisco =Rate of work they all do together

i.e. 
i.e. 
i.e. 
i.e. 
i.e. 
i.e. 
i.e. t= 12
Hence, Francisco would take 12 hours to paint one room on his own.
Answer:
7
/10 0.7
Step-by-step explanation:
To add fractions, find the LCD and then combine.
Which equation are you talking about
I don’t see the pic !
Answer:
20 pens
Step-by-step explanation:
if there is 1 red pen for every 4 blue pens
then
4 red pens would have 16 blue pens with it. makes a total of 20 pens, with 12 more blue pens than red pens