2.3 yd rounded to the nearest tenth

Click on the graphic until you find the right quotient. (36xa - 30xb) ÷ (-6x2)

How do i do this activity, is appreciated

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