If you come across a question where you need to find the value of the variable, the best method is to put the values given as options and then select the one that satisfies the equation.
One of the best tricks is not choosing extreme values in MCQs options. So better to avoid the highest & lowest values.
You may be given 2 correct answer values with different units.
A. 60°CB. 50°CC. 60°KC. 70°C
Do not get tricked by the units, calculate the answer & choose your answer wisely by reading the question carefully.
Be clear with the marking scheme and prioritise those questions that do not carry any negative marking.
When you are stuck between only 2 options, then use either of these methods - avoiding extreme values or choosing options based on units & dimensions.
For e.g., For velocity, the correct answer must have units that have dimension M L T=> 20 ms is incorrect=> 20 m/s is correct.