Please show all your work and write clearly. Thank you

4. Suppose Ches Tahoe restaurant is one of the 7 largest restaurants in X City. a. You would like to choose two different restaurants from them. How many di'erent ways are there? (5 points) b. You would like to choose two different restaurants. One is for your lunch and the other one is for your dinner. How many different ways are there? (5 points) 0. You would like to choose two restaurants. One is for your lunch and the other one is for your dimer. You are OK for going to the same restaurants. How many different ways are there? (5 points)