Three people can wash clothes in 1/3 hrs, 1/4 hrs and 1/4 hrs. If they started together at 8:30 am, at what time will they finish this work together?
*Please anyone to help me out this question*
20 min , 15 min , 15 min
in the combined time (t) , they each do some fraction of the job
... the fractions sum to one (the whole job)
t/20 + t/15 + t/15 = 1 ... LCD is 60
3t/60 + 4t/60 + 4t/60 = 1
3t + 4t + 4t = 60
Since we are going to need minutes anyway ....
rates are: wash/20, wash/15, and wash/15
combined rates = 11wash/60
time to finish the wash with all three washing
= wash/(11wash/60)
= 60/11 minutes
= appr 5.45 minutes
make use of my answer in your concluding statement.
To find out when they will finish the work together, we need to add up the times it takes each person to wash clothes individually and find the total time it takes when they work together.
Let's start by adding up the individual times:
Person 1: 1/3 hours
Person 2: 1/4 hours
Person 3: 1/4 hours
We need to find the least common multiple (LCM) of 3 and 4, which is 12. This means that after 12 units of time, all three people will have completed their individual tasks.
Now we know that in 12 units of time, Person 1 takes 4 units of time, Person 2 takes 3 units of time, and Person 3 takes 3 units of time.
If they started together at 8:30 am, and it takes them 12 units of time to complete the work, we can determine the finishing time as follows:
1 unit of time = 60 minutes / 12 = 5 minutes
The starting time is 8:30 am, which is equal to 8 hours and 30 minutes.
To find the finishing time, we add 12 units of time (60 minutes) to the starting time:
8:30 am + 12 units of time = 8:30 am + 5 minutes x 12 = 8:30 am + 60 minutes = 9:30 am
Therefore, they will finish the work at 9:30 am when they work together.