For all questions, choose the correct answer in the list and give detailed explanation justify your selection?

vii- For a given discharge, the eficiency of sedimentation tank oan be increased by: lecreaning the deroth ef the sank lecreaning the surface and of the tarma Decteasing the depiti bi the lara Decuraking the subtace ares of the tark viii. The coarse screen is normally bept indined at about 4560 to the horizontal, so as to: Decrease the opening arka ia reduce the fow velocity Decrease the opering arna ta inomeie the ficw veloctey ichertale the operieng area to inctilie the flow vilocity is. A water teatment piave of capacty, 1m1A has filter boies of dimensions 6 m10m. The loading rase to the ihes in 170m3/ddxymen2. When two of the fiters are out of service for back weshing the loading rate (inm2/ dopy/me') is x per clapite per day A tapit and fice having an newage fletabion ate of 100 itethourime in is be deigned tor aner teemene the wes of tapid und fite tegilest it (thee the refic of emainum demand as inkigh femand as 15 ) 1450m2 6.00m2 12.10mi 3000m2