Question

A new crew of painters can paint a small apartment in 12 hours and experience crew can paint a small apartment in six hours how many hours does it take to paint the apartment on the true cruise work together

Answer 1

The new crew and the experience crew working together can paint the apartment in 4 hours.

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 =
`(1)/(12)` of the apartment

In 6 hours the experience crew can paint = 1 apartment

So,in 1 hour the experience crew can paint =
`(1)/(6)` of the apartment

Now, the new crew and the experience crew are working together.

So, in 1 hour, they can paint :

⇒
`(1)/(12)+(1)/(6)`

Taking LCD = 12, we will add fraction.

⇒
`(1)/(12)+(2)/(12)`

⇒
`(3)/(12)`

Simplifying fraction we have:

⇒
`(1)/(4)` of an apartment

Again using unitary method to determine the time taken by them working together to paint the whole apartment.

They can paint
`(1)/(4)` of an apartment in 1 hour.

To paint 1 apartment they will take =
`(1)/((1)/(4))=4` hours

Thus, the new crew and the experience crew working together can paint the apartment in 4 hours.