Simplify 2/3^-6 x 3/2^-4

Jack lives on a farm and has a large backyard. the area of his rectangular backyard is of a square mile. if the width of the yard is of a mile, what fraction of a mile is the length of the rectangular backyard?

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 many different three-digit numbers can be formed using the digits 1 comma 2 comma 9 comma 6 comma 4 comma 3 comma and 8 without repetition? for example, 664 is not allowed.