6 hour ride 38.4 killometers

For the rule of 78, for a 12-month period, the last term in the sequence is 12 and the series sums to 78. for an 10 month period, the last term is and the series sum is . for a 15 month period, the last term is and the series sum is . for a 20 month period, the last term is and the series sum is

How to find the exponential function y=ca^x, with points (1,2) and (2,1)

Which angle of rotation is an angle of rotational symmetry for all figures?