I am running issues with these problems in MATHEMATICA software Coding class. I have previously posted the same material but have been getting answers in c++,Java, etc... I thank the great minds on here but, I am ONLY FOCUSED WITH THE MATHEMATICA program. I wanted to compare my work to confirm my progress. So please only answers in Mathematica language. thank u

a. Using a while loop, prompt the user for to input 5 numbers (the input numbers should be 1, 5, 9, 12, 16). The program should sum ONLY numbers that are divisible by 3 b.This program should request numbers, (with -1 to quit). It should ask the user whether they want to add or multiply the numbers. Must use a for add and m for multiply. Complete the operation. The numbers you should enter to be added are 3,2 and 8. To be multiplied 2, 3, 5