Does someone know how to answer number 8, do i have something wrong? i need a bit of !

Given the equation f(x)=a(b)x where the initial value is 40 and the growth rate is 20% what is f(4)

Write the equation in logarithmic form e^x=403.429

For the chance to be team captain, the numbers 1-30 are put in a hat and you get two chances to pick a number, without replacement. which formula correctly shows how to find the probability that you choose the number 1 and then 2?