It takes 12 men 5 days to complete a job. (a) Work out how many days it would take 3 men to complete the same job.

I know that the answer is 20 but I need an explanation

David must install fencing around a lot that is shaped like a right angle.the side of lot that runs east-west is 200 ft long.the side of the lot runs north-south is 125 ft long.calculate how many feet of fencing he will need to surround the entire lot.

Fredrick designed an experiment in which he spun a spinner 20 times and recorded the results of each spin

Abox contains 1 plain pencil and 4 pens. a second box contains 5 color pencils and 5 crayons. one item from each box is chosen at random. what is the probability that a plain pencil from the first box and a color pencil from the second box are selected? write your answer as a fraction in simplest form.