There are 72 new houses being built in a neighborhood. last month, 13 of them were sold. this month, 23 of the remaining houses were sold. how many houses are left to be sold?

Technicians have installed a center pivot, circular irrigator for a farm that covers 25 acres. a.) how long is the irrigation boom (in feet) from the center pivot to its farthest extent? b.) if the irrigation boom makes 4 full revolutions in a day, how many miles does the end of the boom travel in 5 days?