What is 3/8 + 2 1/2? Please Help

Describe all the numbers that when rounded to the nearest thousand are 645,000

Arestaurant gives out a scratch-off card to every customer. the probability that a customer will win a prize from a scratch-off card is 25%. design and conduct a simulation using random numbers to find the experimental probability that a customer will need more than 3 cards in order to win a prize. justify the model for your simulation, and conduct at least 10 trials.

If f(x)=3x+1 and f^-1=x-1/3, then f^-1(7)=