If the Fore Bearing of the lines AB and BC are $60^{\circ}$ and $122^{\circ}$, respectively, then the interior angle $\angle A B C$ (in degrees) is ________ (round off to the nearest integer).

The most suitable test for measuring the permeability of clayey soils in the laboratory is ___________

From a flow-net diagram drawn under a concrete dam, following information are obtained:

(i) The head difference between upstream and downstream side of the dam is 9 m .

(ii) The total number of equipotential drops between upstream and downstream side of the dam is 10 .

(iii) The length of the field nearest to the toe of the dam in the downstream side is 1 m .

If the soil below the dam is having a saturated unit weight of $21 \mathrm{kN} / \mathrm{m}^3$ and unit weight of water is $9.81 \mathrm{kN} / \mathrm{m}^3$, then the factor of safety against the quick condition will be __________ (round off to two decimal places).