$1.$ We send a frame of $256$ bits. If the probability that a bit changes in transmission is $0\mathrm{.}001$ and each bit is independent.

a$.$What is the probability that exactly $6$ bits change?

b$.$What is the probability of no bits changing?

$2.$ If a Signal with a power level of $40$ mW is inserted onto a transmission line and the measured power some distance away is $10$ mW$,$ calculate the loss of signal strength is decibels.

Preferably type the answer instead of sending a picture of a piece of paper.