You take the total number of picture and multiply it by .12, which will get you the total number of black and white photos only.
600(.12)= 72
Pretty sure law. judicial means of, by, or appropriate to a court or judge.
6x/6y=6z
X/?Y=1/2Z
36=6
1hole take 1 man x 6 days
1/2 hole needs 1 man with 3 days