if a tripod settles in the interval that elapses between taking a back sight reading and the following foresight reading. then the elevation of turning point will:

On a plan that was scaled at 1 cm=40 metres, a surveyor measured the distance between two spots, and the result was 450 metres. But afterwards he realised he had been using a scale of 1 cm=20 m. then actual distance between the spots is:

On a plan that was scaled at 1 cm=40 metres, a surveyor measured the distance between two spots, and the result was 450 metres. But afterwards he realised he had been using a scale of 1 cm=20 m. then actual distance between the spots is: