1. Fill in the following gap of RL.
a) 9.9
b) 97.4
c) 95.4
d) 97.9

2. In a two-peg test of a level, the following readings were made:
- Instrument at midpoint between A and B, reading on [tex]$A = 6.350$[/tex], reading on [tex]$B = 4.700$[/tex].
- Instrument at B, reading on [tex]$A = 4.570$[/tex], reading on [tex]$B = 2.900$[/tex].

What is the difference in elevation between the two points?
a) 1.570
b) 1.600
c) 1.700
d) 1.670

3. A surveyor went to the field and recorded the following readings: [tex]$1.320, 1.250, 3.650, 0.670$[/tex], respectively. His temporary benchmark was 43.500. What was his height of instrument?
a) 42.150
b) 44.150
c) 44.830
d) 45.490

Sure! Let's break down each part of this question step-by-step.

Question 1: Unfortunately, we don't have enough information to calculate the gap of RL based on the provided data. Therefore, we can't determine the answer for this part.

Question 2: We need to calculate the difference in elevation between two points using a two-peg test. Here are the readings:

- First setup (Instrument at midpoint):
- Reading on point A = 6.350
- Reading on point B = 4.700

- Second setup (Instrument at B):
- Reading on point A = 4.570
- Reading on point B = 2.900

To find the difference in elevation between points A and B, we use the formula:

[tex]\[ \text{Difference in elevation} = (\text{Reading on A from first setup} - \text{Reading on A from second setup}) + (\text{Reading on B from second setup} - \text{Reading on B from first setup}) \][/tex]

Putting in the values we have:

[tex]\[ \text{Difference in elevation} = (6.350 - 4.570) + (2.900 - 4.700) \][/tex]

[tex]\[ \text{Difference in elevation} = 1.780 - 1.800 \][/tex]

[tex]\[ \text{Difference in elevation} = -0.020 \][/tex]

So, the difference in elevation between the two points is [tex]$-0.020$[/tex].

Question 3: We need to calculate the height of the instrument given the readings:

- Temporary Bench Mark (TBM) height = 43.500
- Backsight reading (first reading) = 1.320
- Foresight reading (last reading) = 0.670

We use the formula to find the Height of Instrument (HI):

[tex]\[ \text{Height of Instrument} = \text{Temporary Bench Mark (TBM)} + \text{Backsight reading} - \text{Foresight reading} \][/tex]

Substitute the values into the formula:

[tex]\[ \text{Height of Instrument} = 43.500 + 1.320 - 0.670 \][/tex]

[tex]\[ \text{Height of Instrument} = 44.150 \][/tex]

Thus, the height of the instrument is 44.150.

So, to summarize:

- The difference in elevation between the two points is [tex]$-0.020$[/tex].
- The height of the instrument is 44.150.