Telescoping sum 1/(sqrt n + sqrt(n+1)) between two limits

The same question, asked 3 times: CDS 2 2020*, CDS 1 2022*, CDS 2 2024. Every wording below, oldest first.

Try each one first, then open its answer.

Question 1
CDS 2 2020
12 $\frac{1}{1+\sqrt{2}} + \frac{1}{\sqrt{2}+\sqrt{3}} + \frac{1}{\sqrt{3}+\sqrt{4}} + \ldots + \frac{1}{\sqrt{99}+\sqrt{100}}$
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Question 2
CDS 1 2022
24 $\frac{1}{1 + \sqrt{2}} + \frac{1}{\sqrt{2} + \sqrt{3}} + \frac{1}{\sqrt{3} + \sqrt{4}} + \cdots + \frac{1}{\sqrt{2020} + \sqrt{2021}}$
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Question 3
CDS 2 2024
8 $\frac{1}{\sqrt{10} + \sqrt{9}} + \frac{1}{\sqrt{11} + \sqrt{10}} + \frac{1}{\sqrt{12} + \sqrt{11}} + \ldots + \frac{1}{\sqrt{196} + \sqrt{195}}$
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Question 1