Question

1)Find S12 for 1 + 6 + 11 + 16 +…

Answer 1

Term 12?

1 + 6 + 11 + 16 + 21 + 26 + 31 + 36 + 41 + 46 + 51 + 56

1    2     3      4      5      6      7      8      9      10    11     12

So it is 56 I believe lol

Answer 2

The rule is +5 each time 
Use the formula: an = a1 + (n - 1)(d)
a1 is the first term which we have is 1 and d is the common difference which is 5 and n is the number of terms so

1 + (12 - 1)(5) = 56 is what I got