Help solve the above equation

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

Find the perimeter of the figure shown above. a. 18 yds c. 20 yds b. 10 yds d. 24 yds select the best answer from the choices provided

How do i multiply two digit numbers