If the size of the ground area is 6 km × 3 km and the corresponding photo size in the aerial photograph is 30 cm × 15 cm, then the scale of the photograph is 1 : ________ (in integer).

A delivery agent is at a location R. To deliver the order, she is instructed to travel to location P along straight-line paths of RC, CA, AB and BP of 5 km each. The direction of each path is given in the table below as whole circle bearings. Assume that the latitude (L) and departure (D) of R is (0, 0) km. What is the latitude and departure of P (in km, rounded off to one decimal place)? 

$$ \begin{array}{|c|c|c|c|c|} \hline \text { Paths } & \text { RC } & \text { CA } & \text { AB } & \text { BP } \\ \hline \begin{array}{c} \text { Directions } \\ \text { (in degrees) } \end{array} & 120 & 0 & 90 & 240 \\ \hline \end{array} $$

A standard penetration test (SPT) was carried out at a location by using a manually operated hammer dropping system with 50% efficiency. The recorded SPT value at a particular depth is 28. If an automatic hammer dropping system with 70% efficiency is used at the same location, the recorded SPT value will be _________.

A vertical sheet pile wall is installed in an anisotropic soil having coefficient of horizontal permeability, 𝑘_𝐻 and coefficient of vertical permeability, 𝑘_𝑉. In order to draw the flow net for the isotropic condition, the embedment depth of the wall should be scaled by a factor of ______, without changing the horizontal scale.