Introduction:
The freezing point on the given thermometer is marked as -20 and the boiling point is marked as 130. We need to determine how a temperature of 34 degrees on this thermometer will be read.

Explanation:
To determine how a temperature of 34 degrees on this thermometer will be read, we need to understand the scale the thermometer is using. In this case, the scale is not mentioned explicitly, but we can assume it to be a Celsius scale.

Celsius Scale:
The Celsius scale is a common temperature scale used in many countries around the world. On this scale, the freezing point of water is marked as 0 degrees Celsius, and the boiling point of water is marked as 100 degrees Celsius.

Converting the Given Markings:
The freezing point on the given thermometer is marked as -20, which indicates that it is 20 degrees below the freezing point of water (0 degrees Celsius). Similarly, the boiling point is marked as 130, which indicates that it is 30 degrees above the boiling point of water (100 degrees Celsius).

Calculating the Conversion Factor:
To determine how the temperature of 34 degrees on this thermometer will be read, we need to calculate the conversion factor. The difference between the given freezing point (-20) and the actual freezing point (0) is 20 degrees. Similarly, the difference between the given boiling point (130) and the actual boiling point (100) is 30 degrees. Therefore, the conversion factor can be calculated as follows:

Conversion factor = Difference in given markings / Difference in actual temperatures
= (130 - (-20)) / (100 - 0)
= 150 / 100
= 1.5

Calculating the Reading:
Now, we can calculate the reading for a temperature of 34 degrees on this thermometer using the conversion factor:

Reading = Given temperature - (Given freezing point)
= 34 - (-20)
= 34 + 20
= 54

Therefore, a temperature of 34 degrees on this thermometer will be read as 54 degrees.

Answer:
The correct option is b) 51 degrees.