How to write 3+12+21+30+39+48 in sigma notation?

Which formula finds the probability that a point on the grid below will be in the blue area? p(blue) = total number of squares number of blue squares number of blue squares p(blue) = total number of squares number of blue squares p(blue) = number of white squares

What is another way to express 36 +32

1) you deposit $2,500 in an account that earns 4% simple interest. how much do you earn in eight years?