The direct and reversed zenith angles observed by a theodolite are 56° 00' 00" and 303° 00' 00", respectively. What is the vertical collimation correction?

A student is scanning his 10 inch × 10 inch certificate at 600 dots per inch (dpi) to convert it to raster. What is the percentage reduction in number of pixels if the same certificate is scanned at 300 dpi?

Trigonometric levelling was carried out from two stations P and Q to find the reduced level (R. L.) of the top of hillock, as shown in the table. The distance between Stations P and Q is 55 m. Assume Stations P and Q, and the hillock are in the same vertical plane. The R. L. of the top of the hillock (in m) is ____________ (round off to three decimal places).

$$ \begin{array}{|c|c|c|c|} \hline \text { Station } & \begin{array}{c} \text { Vertical } \\ \text { angle of } \\ \text { the top of } \\ \text { hillock } \end{array} & \begin{array}{c} \text { Staff } \\ \text { reading on } \\ \text { benchmark } \end{array} & \begin{array}{c} \text { R.L. of } \\ \text { bench } \\ \text { mark } \end{array} \\ \hline \mathrm{P} & 18^{\circ} 45^{\prime} & 2.340 \mathrm{~m} & \begin{array}{c} 100.000 \\ \mathrm{~m} \end{array} \\ \hline \mathrm{Q} & 12^{\circ} 45^{\prime} & 1.660 \mathrm{~m} & \\ \hline \end{array} $$

The specific gravity of a soil is 2.60. The soil is at 50% degree of saturation with a water content of 15%. The void ratio of the soil is _______.