The left one pls help me

What is the y intercept of f(x)=(1/2)^x?

Candice uses the function f(t)=t+100−−−−−−√ to model the number of students in her after-school program. the variable t represents days and f(t) represents the number of students. how many days does it take for there to be 15 students in her program? a. 225 days b. 125 days c. 325 days d. 115 days

Idon't want to fail summer school. the probabilities of contamination in medicine capsules due to the presence of heavy metals and different types of microbes are given in the table. the probability of capsule b having microbial contamination is (the same as, greater than, less than) the probability of capsule d having it.