Alex needs to varnish the top and bottom of a dozen rectangular wooden planks. the planks are 8 feet long and 3 feet wide. each pint of varnish covers 125

We need to first find the area of all the dozen planks, top and bottom.
A=(length)(width)
A=(8)(3)=24 feet squared
24+24=48 feet squared for each plank
Then, you would multiply 48 with 12 since all the planks have the same dimensions.
(48)(12)=576 feet squared in total
Then in order to find the number of pints of varnish needed to cover the dozen planks top and bottom, we need to divide the total area, 576 with 125 which is about 4.608 which means that Alex needs 5 pints of varnish to cover all the planks.

4 pints of varnish

What exactly is your question?