A cistern of capacity 8000 litres measures externally 3.3 m by 2.6 m by 1.1 m and its walls are 5 cm thick. The thickness of the bottom is:

A. 90 cm B. 1 dm
C. 1 m D. 1.1 cm

• Let the thickness of the bottom be x cm.
  
  Then, [(330 - 10) x (260 - 10) x (110 - x)] = 8000 x 1000
  
  320 x 250 x (110 - x) = 8000 x 1000
  
  (110 - x) = 8000 x 1000 = 100
  320 x 250
  
  x = 10 cm = 1 dm.
• 12 years agoHelpfull: Yes(1) No(1)