5132ab is a six digit number that is divisible by both 5 and 11. What is the sum of all possible values of it?

What is the summation of the first 100 numbes that are divisible by 3 without any reminders?

4,5,6,8,14,38,..... What is the next number of this sequence? 

For a positive real number x, let [x] be it's integer part. For example, [3.14]=3, [5]=5, [6.9]=6. Let z be the largest real number such that [3/z]+[4/z]=5. What is the value of 21z?