Answer:
Wdym
Step-by-step explanation:
Mathematics value in words
Let's pick one person at random and call it the 'first'.
That person shakes hands with 29 other classmates.
Take another person different from the first, we'll call him the 'second'. Since he has already shaken hands with the first, he shakes hands with 28 other classmates.
The 'third' person will likewise shake hands with 27 other classmates, and so on.
Hence, the total number of handshakes is 29+28+27+...+2+1 = 29*30/2=435 handshakes
Answer:
E (Y) = 3
Step-by-step explanation:
If a 4-sided die is being rolled repeatedly; and the odd-numbered rolls (1st 3rd,5th, etc.)
The probability of odd number roll will be, p(T) = 
However, on your even-numbered rolls, you are victorious if you get a 3 or 4. Also, the probability of even number roll, p(U) = 
In order to calculate: E (Y); We can say Y to be the number of times you roll.
We know that;
E (Y) = E ( Y|T ) p(T) + E ( Y|U ) p(U)
Let us calculate E ( Y|T ) and E ( Y|U )
Y|T ≅ geometric = 
Y|U ≅ geometric = 
also; x ≅ geometric (p)
∴ E (x) =
⇒
= 4 ; also
= 2
E (Y) = 4 ×
+ 2 ×
= 2+1
E (Y) = 3
Well if the student already finished 6 problems out of 15, there are 15-6 = 9 homework questions she still has to finish.
Still needs to complete: 9.
Already finished: 6
9 : 6.
Simplified: 3 : 2