Please help! i do not understand

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

If a flying disk is 139 meters in the air and travels at an average of 13 m/s how long is it in the air

Identify this conic section. x2 - y2 = 16 o line circle ellipse parabola hyperbola