I need help with these questions from my microsoft visual basics class. Thanks a lot in advance!~

3. Write For...Next loops that calculate the sum of the following ranges and assign their sum to a variable named intSum: a. The first 50 numbers starting with b. The even numbers beginning at 10 and ending with 100 c. The numbers 20, 30, 40, 50, 60, 70 and 80 4. Find the error(s) in the following For...Next header statements a. For intCounter = "1" TO "19" b. For strNumber = 98 TO 71 Step 2 c. For intValue 12 To 52 Step -4