Alumberman stacks planks of wood, starting with 30 planks in a row. each row he stacks has one less plank than the row below it. the last row he stacks has 15 planks. how many rows of planks has he stacked?
12
15
16
18

3, 12, 48, 384, 1536, 6144, 24576, 98304

step-by-step explanation:

just keep timing it by 4.

answer: $201

step-by-step explanation: to get the answer, you first get 3 nieces that he sold and multiply it by 67 and get $201, so he earned $201 selling his nieces.