A cylindrical tank of diameter 35 cm is full of water. If 11 litres of water is drawn off, the water level in the tank will drop by-

2.8cm

i think it is 11.43cms

because

1 dm^3=1L

11L=11dm^3

which is 11000 cm^3

equate it to volume of the cylinder formula;

11000=(22/7)*(35/2)^2*h

solving for h

h=100*4/35

=11.42857~11.43cms