Question

the house will be constructed by the construction workers in a year​

Answer 1

Answer:

what to do in this sentence

Answer 2

Answer:

If 10 workers need 3 days to build 1 house then 1 worker needs 3 x 10 = 30 days to build 1 house.

So rate of work is 1 house / 30 worker days effort

So with 15 workers you get this 30 worker days effort in 30/15 = 2 days

So 15 workers would need 2 days to build a house

At this rate, to build 4 houses 15 workers need 4 x 2 = 8 days.

But this is if life was only maths. In real life 15 workers may take more time than 10 workers due to other factors like relevant skill set & team coordination.