If the 10th term of an Arithmetic Progression (AP) is 21 and the 17th term is 8 more than the 13th term, then find the AP.

The first term of an AP is 3 and the common difference is 2. Find the 50th term.

Find the sum of the series: 3 + 5 + 7 + 9 + ... + 43

Find the sum of all three-digit numbers divisible by 9.