.
1-st senator in the committee can be any one of 100 senators, giving 100 options.
2-nd senator can be any one of 98 senators from other states, giving 98 options.
3-rd senator can be any of 96 senators from remaining 48 states, giving 96 options.
In all, there exists 100*98*96 = 940800 different ways. ANSWER
Solved.
================
My note after reading the post by @Math_tutor2020.
@Math_tutor2020 correctly pointed that my number must be divided by 3! = 6:
940800/6 = 156800.
I agree with it, in full (!)