11.00100100001111110110… is an approximation, in binary, of a mathematical constant relating to what?

Question

In this teaser you are required to find a word relating to mathematics hiding in consecutive letters within each sentence. Have fun!

Example:

"They knew that they had done the wrong thing."

Answer: ADD located in: "...hAD Done..."

1. The governor gave the budget a cut everywhere possible.

2. It is rumoured that Capri men often marry Naples women.

3. He drove his new Mustang entirely too recklessly.

4. Groucho and Harpo were two of the Marx brothers.

Answer 1

A circle's circumference and diameter
It is pi (p = 22 / 7)