Work it exactly like the other one with Wilda and Karla.
Juan takes 15 hours to do a job ... he does 1/15 of it in an hour.
His father can do it in 6 hours ... he does 1/6 of it in an hour.
Juan works alone for 4.5 hours. In that time, he does 4.5/15 = 0.3
of the job. When his father joins him, there's only 0.7 of it to finish.
Working together, they do (1/15 + 1/6) = (2/30 + 5/30) = 7/30 of the job
each hour.
How many times do they have to do 7/30 of the job in order to finish
the 7/10 of it that remains ? That will be the number of hours they need.
(7/10) / (7/30) = 7/10 x 30/7 = <em>3 hours</em>.
Then they can knock off while it's still daylight, and go for a swim.
Mr. Toshio had 32 rulers.
32-11 = 21 rulers.
21+4 = 25 rulers.
and
25-7 = 18 rulers
Answer: after 3 days
Step-by-step explanation: Step-by-step explanation: The sister has to pay rent which is $60 which means she has negative $30 in three days the sister would have earned $60 and in 3 days the brother would have earned $60
Answer:

Step-by-step explanation:
The perimeter is two times width plus two times length:

There is no way to simplify further.