Answer:
The new crew and the experience crew working together can paint the apartment in 4 hours.
Step-by-step explanation:
Given:
Time taken by new crew of painters to paint an apartment = 12 hours
Time taken by experience crew of painters to paint an apartment = 6 hours
To find the time taken by them to paint the apartment working together.
Solution:
Using unitary method to determine their 1 hour work.
In 12 hours the new crew can paint = 1 apartment
So,in 1 hours the new crew can paint = of the apartment
In 6 hours the experience crew can paint = 1 apartment
So,in 1 hour the experience crew can paint = of the apartment
Now, the new crew and the experience crew are working together.
So, in 1 hour, they can paint :
⇒
Taking LCD = 12, we will add fraction.
⇒
⇒
Simplifying fraction we have:
⇒ of an apartment
Again using unitary method to determine the time taken by them working together to paint the whole apartment.
They can paint of an apartment in 1 hour.
To paint 1 apartment they will take = hours
Thus, the new crew and the experience crew working together can paint the apartment in 4 hours.