Tasha earns $400 per week plus a commission of 10% on her weekly sales. each week she saves of her earnings. in the expression , what does the expression 400 + 0.1s represent in this situation?

F. a fair coin is thrown in the air four times. if the coin lands with the head up on the first three tosses, what is the probability that the coin will land with the head up on the fourth toss? a. 0 b. 1/16 c. 1/8 d. 1/2