T. J. is hosting a dinner party. T. J. greets the first guest and they shake hands. The second guest arrives and shakes hands with T. J. and the first guest. The third guest arrives and shakes hands with T. J., the first guest, and the second guest. This pattern continues. How many handshakes have taken place after the ninth guest arrives?

45 Handshakes

Step-by-step explanation:

45 Handshakes have taken place all together

sorry not sure

step-by-step explanation:

answer:   35 % is the probability of a late departure or an early arrival.

step-by-step explanation:

let l represents the late departure and e represents the early departure.

then, according to the question,

p(l) = 12 %,   p(e) = 27 % and = 4 %

and, we have to find out,

but, we know that,

which is the required equation that will use to find the probability of a late departure or an early departure.

therefore,   the probability of a late departure or an early arrival =   35 %